This is a quick note (mostly to myself) to say that the computer hosting www.malak.ca — the website hosting this blog — has been switched out and replaced.
Last night, I was able to access the site normally and remotely while out to dinner at the home of some friends. This morning, in trying to ssh into the machine to do a routine manual software update, the connection kept timing out and disconnecting. Some quick diagnostics along the lines of “is the machine plugged in?” and a few reboots to watch was what happening — about as much as it would allow me to do, in fact — revealed that for reasons unknown, it was rebooting, going through a grub page, booting up, showing the Fedora logo, and, after the logo disappeared but before the login prompt appeared, a bios message came on the screen indicating a signal loss, and a reboot would begin again.
I tried a few past kernels in the grub menu, including the rescue kernel, and checking the bios, to no avail. Bringing up the text display of what was going on during the bootup was hard to access since I was scratching my head wondering “What’s the keystroke to do that again?”; same for getting the console. No matter, other things needed attending to in the moment, and I moved on.
Fortunately, my brother-in-the-know was coming within the hour, and I sent him some messages about it. He offered to bring an old junk-computer-which-wasn’t-quite-junk-yet I had given to him a while back and which he wasn’t using, at least not yet. After describing the problem to him and offering my rough diagnosis — either there was a corruption somewhere in the software, causing the reboots, or, during the reboots software commands invoke a (presumably faulty due to old age) physical hardware system or circuit, which caused a problem leading to the reboots — both of which, particularly the latter, he thought may have had merit.
My brother brought the old machine. Before installing anything, he first checked the OS SSD from the server (which also contains this blog’s database) in a USB caddy, then he checked the external data drive holding the rest of the static website and my backups, again by USB. Data on both units were in good condition. We finally went straight to replacing the machine by transferring the SSD and external drive to the new old machine, and here I am typing up this memo to myself.
The machine’s specs?
Dell Vostro 420 series; 8.0 GiB; Intel Core2 Quad Q9400 x 4; Mesa Intel G45/G43 (ELK) video card, with lots of USB ports, a networking card, and other things many people including myself take for granted.
And since the 240.1 GB SSD is the drive from the previous machine, it is still running the same instance of Fedora and the LAMP stack with WordPress, suffice it to say that I’m up to Fedora Linux 37 (Workstation Edition) 64-bit on it, and running up to date LAMP and WordPress software.
In fact, as I am finishing up this post, the machine is being updated!
This post is a translation of and (somewhat of an) adaptation, as well as slight update, of a presentation I gave in November, 2021, at a meeting of my local Linux Meetup. This adaptation includes some extra limited mockups of demonstrations performed live during the presentation.
The presentation was put together using Fedora Workstation (a general purpose version of Linux, in this case specializing in being a desktop workstation), highlighting some software either installed by default, or available in the Fedora Linux and rpmfusion software repositories (“App Stores”). It is therefore not intended to be a complete exposé on all available open source / free software options for PDF, even under Fedora Linux, let alone GNU / Linux in general, or other systems.
It should be noted that the presentation’s original target audience was a French-speaking group of Linux enthusiasts, Linux professionals, and other IT enthusiasts and professionals familiar with Linux. Most of the listed software would typically be available in standard or easily accessible Linux software repositories (“App Stores”). Beyond the world of GNU / Linux, free software is generally available for use on other systems, and, barring instances of a specific given package offered with paid warranty support, are usually also free of charge to download, install, and use.
In the case of the software highlighted in this post, all are either free-of-charge, or represent the free-of-charge version.
The Value of a PDF File
Context / Situation:
Take the case of the exchange of a document between two computers — such as between one running Linux, and another running Windows (or vice-versa) — and each computer is endowed with a different office suite, such as LibreOffice (cross-platform) on one, and Microsoft Office (Windows / Mac) on the other. (Of course, other possibilities exist, such as Calligra Suite (cross-platform), Pages / Numbers / Keynote / etc. (Mac), Corel Wordperfect, Google Docs, etc.)
LibreOffice, and in days gone by, OpenOffice.org, have long been touted as being “compatible” with MS Office; this purported compatibility, however, is disappointingly nowhere near as good as I and many others would like to believe.
As such, each user will open the shared document, which will be displayed according to each suite’s interpretation of the file, and may find that the actual displayed content on their screen could be different — sometimes substantially so — from the intended original display of the document. Text lines may be cut off; fonts may not be available on one or more of the systems, causing font substitution; font sizes may be changed, or text size may be different while substituting a different font due to the lack of the specified font; certain symbols may not be available on some systems; table effects may not work, or objects inserted into tables may not function or be displayed as expected, such as the insertion of a spreadsheet.
Unfortunately, I would estimate that said disappointing lack of “complete and perfect” “drop-in replacement” compatibility is a very common experience in comparing many well-known pieces of proprietary software and their open-source counterparts — not just LibreOffice and MS Office. Personally, as a Linux user, I have experienced this lack of complete compatibility a number of times since beginning to use OpenOffice.org in 2005 and Linux in 2006. Since then, I have also seen the incompatibility in action on a number of occasions during varying presentations under completely unrelated circumstances in which the presentation files were produced in one suite, and attempts made to show them in another were met with varying degrees of disappointment, sometimes leading to complete failure.
Example PDF
The PDF at this link is a somewhat varied although basic document created for this presentation (you will need a PDF viewer); images of the PDF are shown below. It was developed in order to use throughout the presentation as an example PDF to demonstrate the various given points at hand. It should be noted that the PDF was written in French because the presentation’s original target audience was French-speaking.
The following four images are jpeg images of the pages of the PDF document linked to above, and which I created in LibreOffice Presentation. It should be noted that, for the sake of argument, the pages could have been created in another format, such as a word processor, a spreadsheet program, or a drawing program, for instance.
Page 1 — Song lyrics to be displayed for a Karaoke Night
Page 2 — Expenses list for a Luncheon
Page 3 — TV Listings
Page 4 — Flea Market Poster
The above document — represented here in jpeg format directly produced from a PDF of the document — was originally prepared in LibreOffice Presentation, and therefore correctly represented the original document.
However, the following four images are jpeg images of the pages of the PDF document I created in Microsoft PowerPoint (you will need a PDF viewer) into which I imported the original LibreOffice Presentation, in order to demonstrate the relative lack of compatibility between, at least in this case, LibreOffice Presentation and Microsoft Powerpoint.
Page 1 — Song lyrics to be displayed for a Karaoke Night
Changes: Text fonts and font sizes, causing text to be cut off the page
Page 2 — Expenses list for a Luncheon
Changes: Text fonts, and improper translation of symbols
Page 3 — TV Listings
Changes: text fonts, font sizes, and lack of background colours in the various cells
Page 4 — Flea Market Poster
Changes: Text fonts, font sizes, corrupted translation of spreadsheet table in the centre of the flyer
The value of a PDF:
PDF files are generally well supported across multiple platforms and software, generally regardless of platform, and will usually be displayed in a virtually identical fashion on all systems; in the case of discrepancies, they are usually inconsequential.
However:
There exists a certain perception that, short of having Adobe Acrobat Pro (a commercial, closed source piece software), PDF files are difficult to edit and modify, allowing for a certain view that PDF files are more secure. This is a case of “security by obscurity”, since editing and modification may be performed by many pieces of software, besides but of course including Adobe Acrobat Pro.
PDF files may also benefit from a perception of being less susceptible to viruses and malware, such as through macros. Suspicious files, regardless of format, should always be checked when there is reasonable doubt, particularly under certain environments.
Warning:
Be careful when using some PDF software downloaded from random websites on the internet, or websites which advertise PDF modification: The may add watermarks to the resulting file — this may be undesirable, and embarrassing, particularly if the software, website, or their output aren’t vetted prior to distributing the resulting file.
Further, websites providing PDF editing services may have very reasonable terms of service for editing your document, limiting their responsibilities toward you. By submitting a document to an external website, it may may not be able to protect personal privacy, nor be able to guarantee to not divulge commercial or industrial secrets or confidential personal information contained in the submitted document: They may become the victim of a hacking, or become the target of legal proceedings, not to mention potential dubious or unscrupulous intentions operators might have to begin with. Or, they may simply be unwilling to formally engage in such responsibilities in the absence of a paid service contract.
This article’s objectives therefore are:
Firstly, presenting the utility of PDF as a useful format for distributing documents to a wide audience, without having to concern oneself with what software individual audience members may or may not have access to, if at all, and regardless of reason(s);
Secondly, presenting safe, free software and open-source software options for using and editing of PDF files;
Thirdly, beyond the general promotion of free and open-source software and PDF editing, this article is not about promoting nor deriding particular OSes or software packages, or strictly speaking their strengths or weaknesses.
As such, if a particular system or software package suits your needs and / or purposes, you should use it.
However, if a given preferred solution is costly software, perhaps your organization (or your family) may find it to be financially worthwhile to only purchase a minimum number of licences and only install it on a minimum number of designated computers, instead of needlessly on every computer in your organization (or family).
A simple cost / benefit analysis would be worthwhile: You should consider whether you wish to pay $5, $10, $15, or more, on a recurring basis (perhaps monthly), per computer on which such software would be installed. The costs, be they one-time costs or recurring, should be considered against how often the software may be used, perhaps in some cases only once or twice monthly — perhaps overall, let alone for each individual instance, depending on your organization’s size, needs, and other considerations. Further, it should be considered what operations are typically executed, especially if they simple operations such as joining multiple PDFs, or extracting a page or two, which can be easily performed by many, using any of a multitude of software packages you can get without cost, as opposed to perhaps more technical tasks which may justify costly specialized software.
Creating PDFs from an established document
To begin with, most software which create documents will have an option in the File menu or elsewhere to Print, or Print to Document, or an Export function, which will offer PDF as a format:
At the risk of skipping ahead to the PDF splitting section below, note that it is a common option to be able to selectively output some, instead of all, pages to the resulting PDF, thereby avoiding the question of having to later split the PDF to get only the desired page(s).
Overview of PDF Software
Perhaps (or perhaps not) to the surprise of many, there are many software packages and suites which will:
Display PDF files
Combine, divide, and export PDF files, as well as reorder pages within a PDF;
Edit PDF files, such as the overall files and the file metadata, as well as the PDF file content
Import and display PDF files according to particular strengths (The Gimp, Inkscape, e-readers)
Displaying PDF files:
Here are some examples of software which will display PDF files directly:
Evince Document Viewer (Gnome Project)
Okular (KDE Project)
Firefox and Chromium (Web Browsers)
PDFSam (limited free version; there is also a commercial version with more capabilities); a version for Debian derived Linux systems is available on their website
Here is a very short list of software which will open and display PDF files and allow editing, each according to their strengths, but whose primary function is not PDF display:
LibreOffice (Office Suite)
Calligra (Office Suite)
The Gimp (Image Manipulation)
Inkscape (Vector Graphics Editor)
Evince Document Viewer
Chromium (web browser)
Okular
Software to Combine PDF files
A relatively common activity is to combine multiple PDF files into one file — such as, separately scanned pieces of paper, or PDF files produced separately, perhaps by different people.
Here are some examples of software which will combine PDF files:
PDF Mix Tool
PDF Arranger
PDF Mod
PDF Jumbler
PDFedit
PDFTricks
PDFSam
LibreOffice
Calligra Suite
The Gimp
Combining PDF files in PDFArranger
Software to Divide PDF Files / Extract Pages
Another relatively common activity is to divide a PDF File, or extract one or more pages from a PDF file.
Note that if you are the creator of the document, as shown earlier, the software you used to create the document likely allows for you to selectively export individual or multiple pages to PDF in addition to exporting the entire document.
Here are some examples of software which will divide PDF files / extract pages:
PDF Mix Tool
PDF Mod
PDF Jumbler
PDFedit
PDFTricks
PDFSam
LibreOffice — allows to print and / or export one or more pages
Calligra Suite — allows to print and / or export one or more pages
The Gimp — allows to print and / or export one or more pages
Splitting a PDF File with PDFMod
PDF Editing
Here are some examples of software which will edit PDF files to varying degrees:
LibreOffice permits the possibility of creating a hybrid PDF and .odt / .ods file (word processor or spreadsheet files), which will allow for the PDF to be more easily edited by any suite that is able to edit .odt and .ods files; create a document with LibreOffice, and in creating a PDF, choose Export — General — PDF Hybrid (incorporating .odt / .ods file)
In my personal experience, PDF editing — and ease of doing so — can vary wildly according to what one wishes to do, as well as wildly according to the nature of the source PDF. I have had excellent experiences editing a PDF created from a CAD software drawing (presumably created using commercial CAD software such as AutoCAD), and whose individual elements could be manipulated in LibreOffice Draw. I have also used LibreOffice Draw to insert text zones, arrows, and scanned signatures into PDFs. Conversely, documents composed primarily of scanned images — including text and forms — may require more image manipulation skills to edit, modify, and manipulate individual and specific elements of the document, depending on your objectives.
What you can do will also be dictated by which software package you choose and its strengths and weaknesses.
For instance, it should be noted that the phrase “Editing a PDF” can be a nebulous thing which can mean many and different things to many and different people. For instance, actually editing document text directly in the PDF may be what one understands and expects, while the strengths of a given piece of software may lay elsewhere.
LibreOffice has some PDF import functions, as well as imperfect document layout functions. Depending on the source PDF document, it can be quite effective at editing text directly.
Note from the closed-source world: I once had an excellent experience with a moderately-difficult-to-edit PDF using Microsoft Word, which included being able to edit the text — and presumably save in MS Word’s native file format.
Importing and editing a PDF in LibreOffice Draw (note the imperfect import):
In the case of my example PDF, LibreOffice Draw allows for some direct editing of the text (Notice the word “MODIFIÉ” with a brick-red text colour replacing some of the text):
Importing and editing a PDF in Scribus, a desktop publishing programme:
The Gimp can insert text zones into a PDF, and which text zones themselves may be edited within The Gimp; however, its strengths lie in dealing with a PDF as an image, and editing image characteristics, while editing the text as one might in a word processor might be more challenging.
Importing a PDF file into The Gimp, image manipulation software:
Adding a text zone to a PDF in The Gimp:
Exporting Text, Cut & Paste, and .odt File Creating
Depending on the source PDF and its nature, “cut & paste” may work (as opposed to not working at all), and may even “work well”, although this may be wildly variable according to the source PDF document. However, even in the best case, this method will normally only copy the actual text, and some of the images, from your PDF document; it may not usually be particularly useful in actually replicating the PDF document formatting.
As for other document and content formats, such as drawings, pictures, and text rendered into images, other sections of this post should be consulted (ie. using LibreOffice Draw or The Gimp for drawings; optical character reading (OCR), including OCRFeeder, etc.)
In addition to the mention of LibreOffice above, OCRFeeder is software that acts as a front end to optical character recognition software, and is able to import PDF files, and then export in HTML, plain text, OpenDocument (.odt) format, and of course PDF. Again depending on the source file, results may be variable, although the results are usable.
… and here is an image of the exported .odt file (word processor file) of the page viewed and created in OCRFeeder, then opened in my word processor (LibreOffice):
Ironically, as this case shows, the changes (or lack of adequate recognition and / or translation of the original layout) can be as great or even more as can occur by simply sharing documents between not-fully-compatible-though-similar software suites. However, though far from perfect, it is arguably usable, depending, of course, on how much effort you are willing to devote to replicating the original document layout — and then making your desired changes, and finally creating a new PDF document.
Exporting to other file formats:
As has been (indirectly) demonstrated several times throughout this post, PDF files can be imported into software that isn’t specifically dedicated to PDFs, and then allow for the resulting imported file to be exported into other formats. For example, The Gimp was used to create most of the working images for this post: In the case where PDF files were to be displayed, the PDF files were imported into The Gimp, and then exported in jpeg or png formats. This type of conversion — from PDF to another given format — can often be done by other pieces of software (to varying degrees) according to their strengths or weaknesses.
Photo Editing with PDFs
The Gimp is fully functional image processing software, very similar to — but, unfortunately, not fully compatible with nor a perfect drop-in replacement of — Photoshop. Using The Gimp, you can import a PDF and edit the image(s) directly, or extract photos and other images through a variety of means, such as selecting the area of the photo, copying the selected area, and creating a new document from the clipboard.
Here is a The Gimp having imported a PDF of a photo of myself on a cruise:
During the live presentation, I gave the hypothetical example — for the sake of levity — of a barber who particularly likes sideburns, and seeing mine in a PDF, decided to clip out one of my sideburns from the photo …
… and then notice on how I was starting to go grey at the time :
It is taken as an understood that use of The Gimp to manipulate the photo can be continued at this point — such as how my sideburns might look after a colouring, or to compare side-by-side against other people’s sideburns — and then the result exported as a PDF.
PDFTricks allows for resizing of images in PDFs, principally compressing and reducing the file size to the order of “large”, “medium”, “small”, and “extra-small”, as well as image exporting to .jpg / .png / .txt formats, and file merging and splitting.
During the presentation, the PDF document above composed of the photo of myself on a trip was run through the software’s “extreme compression” option. The following is a clip from a screenshot from a file manager, showing the size difference between the the original file, and the newly created compressed file:
LibreOffice Draw allows for some image manipulation.
In this particular situation, the night sky drawing in the karaoke page of the example PDF I created was selected, and the various options directly available were shown. However, as mentioned earlier, I have imported PDF documents of building plans and modified them to include notes showing were works were performed, or to add signatures to documents.
PDF Forms
PDF Form Creation
LibreOffice Writer and Calligra Suite are fully-featured for the creation of forms. Unfortunately, I am not particularly adept at creating forms.
Filling PDF Forms
Evince — if the PDF form was designed to be interactively filled
Okular — if the PDF form was designed to be interactively filled
The Gimp — allows for text areas to be inserted, as well as photos, drawings, and the like
LibreOffice Draw — allows for text areas to be inserted, as well as photos, drawings, and the like
Viewing / displaying PDF files : User’s choice (usually a system’s default PDF viewer is adequate, or a web browser)
Combining and splitting PDF files : PDFMixTool
Editing PDF files : User’s choice (depends on objectives and source file; The Gimp and LibreOffice Draw are good contenders)
Adjusting PDF file size : PDFTricks
Form creation : User’s choice
Form filling : User’s choice (usually a system’s default PDF viewer is adequate, or a web browser)
Exporting PDF to other formats : OCRFeeder (for .odt); LibreOffice Draw (Photos and images); The Gimp (photos and images)
Note on Linux availability of the above software:
Here are some screen shots from my system’s installed repositories (Fedora Stable; Fedora Updates; rpmfusion.org — free and non-free)
PDF software easily accessible from my computer’s software repositories (“App Stores”):
As this list suggests, there is lot of software available which have varying PDF abilities, ranging from being dedicated PDF software of various kinds, to other pieces of software with other principal functions but with PDF functions ranging to simple importing from and exporting to the format, to being useful within the limits of the software’s main functions to manipulate PDF files in some way(s).
Summary:
This presentation’s goals are to highlight:
how PDF files are well supported most of the time on most systems, while the various pieces of software, between two versions, typically a well-known closed source project and an open-source counterpart, for document production, are not as compatible with each other as we may want;
free software while avoiding the security risks inherent to using unknown and potentially dangerous websites, as well as software which is easily available for routine tasks as well as to reduce costs;
the possibility of editing PDF files with various pieces of free software which are easily available in most Linux distributions’ repositories — as well as often easily available for other platforms — albeit occasionally with variable success.
Questions taken during the presentation:
A question asked midway through the presentation expressed a certain surprise that The Gimp can be used to edit PDFs. As mentioned earlier, The Gimp is able to import PDF files, and perform various functions on the file according to its strengths (image manipulation).
A participant asked at the end during a question period about a recommendation for software to affix signatures to documents. I replied that I was not aware of any open source official signing software with digital traceability, simply because that I had not done any research on that subject; however, an image of a scanned signature can usually be inserted in a document using The Gimp or LibreOffice Draw, or as a document is being created in a word processor.
A final comment recommended the use of LibreOffice Draw, based on the commentor’s frequent use of it to perform a number of the functions listed here, to which I’d commented that I had asked my employer’s IT department to install LibreOffice on my work-issued Windows-based laptop computer in order to be able to perform some drawing-modification functions as part of my employment.
Enjoy sharing and editing PDF files!
UPDATE 20220407:
Signing PDFs can be performed with jPDF Tweak.
JPDF Tweak can also encrypt and add passwords to a PDF.
Over the past at least twelve years, I have been salvaging computers I have found on the streets on garbage day, or found in other locations where my various personal travels have taken me, for use to reformat into usable computers. The various finds have served as main desktop computers, secondary computers, home servers, computation nodes for the World Community Grid, gifts to my brotheror the occasional friend, and the like. It has variously allowed me to indulge in a bit of tinkering, trying out a new linux distro or version of BSD, build a home server, or just pass the time while engaging in a hobby.
In the process, I’ve watched the lower bar of what is acceptable “junk that isn’t junk, at least not yet” move upwards from about P4-533 MHz 32 bit processors to dual core 2.66 GHz 64 bit processors (although single core 64 bit P4 at 3.4 GHz to 3.8 GHz range is good if you don’t want to depend on a GUI, or if you have a lot of RAM and an SSD), 512 MB of RAM to 2GB of RAM, and 20GB hard drives to 80GB hard drives. Now it seems that the next big thing will be in moving from mechanical drives to SSD drives, which I expect — when SSD drives become common in the old computers I find being thrown out — will make a revolutionary change upwards in speed in low end hardware, the way I learned the same in 2017 when I swapped out the mechanical drive in my laptop and replaced it with an SSD. (To be fair, when I bought the computer new in 2015, the hard drive was curiously a 5400 RPM model, presumably either to make it less expensive, less power hungry vis-à-vis battery life, or both.)
As an aside: My favourite brands of castoffs have been, in order, IBM / Lenovo ThinkCentres, then Dells. After that, I’ve had an excellent experience with a single used HP desktop that has been doing computations for World Community Grid running at 100% capacity, since late summer 2016. I’ve dealt with other types of computers, but the ThinkCentres and the Dells have been the ones I’ve had the most success with, or at least the most personal experience. (Since initially writing this post, I have been developing a suspicion that based on the longevity of the HP cast-off I have, HP actually might be superior to the IBM / Lenovo when it comes to cast-offs; however, since it’s the only HP cast off that I can remember ever having, it’s hard to form a proper opinion.)
But to wit: Over the past two weeks, I have tried to revive three used computers that were cast-offs.
Two of them were IBM / Lenovo ThinkCentres, which I think were new in 2006 / 2007, 2.66MHz 64 bit dual cores, 80GB hard drives, and 2 GB memory. The third computer was a Dell case with only the motherboard (proving to have been — see below — a 64 bit dual CPU running at something like 2.66MHz) but no memory, no hard drive, no wires, no DVD player, and not even a power supply!
The two ThinkCentres were from a pile of old computers marked for disposal at a location where I happened to be in mid-2017, and I was granted permission to pick and choose what I wanted from the pile. I gave them to my brother, who at the time evaluated them and determined that neither worked, one just beeping four times and then hanging. After that, they just sat around in his apartment for whenever they might come in handy for spare parts. He had since determined that one actually worked, but he hadn’t done anything with it.
The third computer was found on the street near home a couple of months ago, and was covered with about an inch of snow by the time I’d recovered it. I brought it home, and let it sit around for several weeks just to make sure that it dried out properly. Based on the “Built for Windows XP” and “Vista Ready” stickers, I’d guess that it was new in about 2005 or 2006.
Having forgotten about the ThinkCentre computers I’d given to my brother in 2017, I casually asked him if he had the requisite spare parts to make the snow-covered computer work, since we normally share our piles of spare parts retrieved from old computers that die. To my surprise, he sent me the functional ThinkCentre. My knee-jerk reaction was “I don’t need a new-to-me computer; just the parts required to see if I can get the snow-covered computer to work.” Perversely, I didn’t actually want the results of my planned efforts to produce a functional computer; I just wanted the amusement of a small project, and more generally to see whether the Dell found on the street would work.
In parallel, my home server on which I hosted my backups and my website, another computer of the used several times over variety, worked perfectly except for mysteriously turning off on its own a couple of times recently, perhaps once a week. My brother and I decided that what was probably happening was the result of one or more thermal event(s) which shut down the computer, no doubt due to a combination of dust accumulation, the CPU fan ports in the case not having enough clearance from the computer next to it to allow for proper aspiration of ambient cooling air, and possibly high heat generation from occasional loads due to search engine bots crawling my website. Despite cleaning out the dust, removing the computer’s side panel from which the CPU fan drew air, and shifting both computers a bit in order to allow for adequate ventilation, the computer turned itself off again after about a week.
My brother and I made a swift decision to replace my server with a new installation on a “new” computer — the good ThinkCentre I initially didn’t want — because even though the existing machine was otherwise performing spectacularly well given the overall small load, we tacitly agreed that the shutdowns were a problem with a production server, though we hadn’t actually said the words. This incidentally dealt with another curious behaviour exhibited by the existing server which appeared to otherwise be completely benign, and hence perhaps beyond the scope of why we changed the physical computer.
The operational ThinkCentre was plugged in, formatted with Fedora 31, and my brother helped me install the requisite services and transfer settings to the new server in order to replicate my website. Newer practices in installation were implemented, and newer choices of packages were made. For instance, the “old” machine is still being kept active for a bit as a backup as well as to maintain some VPN services — provided by openVPN — for the purposes of setting up the new server and installing WireGuard for VPN on the new server, and generally allow for a smooth transition period. Other things that we had to remember as well as learn, perhaps for another time, were to install No-IP as a service, and that drive mounts should be unmounted and re-mounted through rc.local.
One of the unexpected bonuses to the upgrade is that it appears to be serving web pages and my blog a wee bit faster, for reasons unknown.
In the meantime, on the next project, I got the non-functional ThinkCentre for its spare parts. The first idea I had was that maybe this second ThinkCentre might still be good, and we looked at a YouTube video that suggested cleaning out the seats for the memory sticks with a can of clean compressed air. I was suspicious of this but let it go for a while, and I proceeded to harvest parts from the computer after deciding that the machine wouldn’t work regardless.
A power supply, cables, a hard drive, and memory sticks were placed in the Dell found on the street. It powered up, and after changing some settings in the BIOS, I was able to boot up a Fedora 31 LiveUSB. Using the settings option from the Gnome desktop, I was able to determine that there was a 64 bit dualcore CPU running at about 2.66GHz, that the 2GBs of memory I’d inserted worked, and that the 80GB hard drive was recognized. I looked around on the hard drive a bit with a file manager (Nautilus) and determined that the place from which I’d retrieved the ThinkCentre appeared to have done at least a basic reformatting of the drive with NTFS. I didn’t try to use or install any forensic tools to further determine whether the drive had been properly cleaned, or had merely received a quick reformat.
Suppertime came around, and the machine was left idle to wait for my instructions for about an hour or so. When I returned to the computer, I saw an interesting screen:
(If you can’t see the picture above, it’s an error screen, vaguely akin to a Windows Blue Screen of Death.) After a few reboots, all with the same “Oh no!” error screen, my brother suggested that the machine may have been thrown out for good reason, intimating that it was good luck that I’d even managed to boot it up in the first place and look around a little bit. I, on the other hand, was relieved: I’d had my evening’s entertainment, I’d gotten what I wanted in the form of working on the machine to determine whether or not the machine could be used, and I’d learned that it indeed couldn’t be used. Parts were stripped back out of the Dell, and the box was relegated to the part of the garage where I store toxic waste and old electronics for the times I have enough collected to make it worthwhile to go to an authorized disposal centre.
At this point, something was still bugging me about the second ThinkCentre. I hadn’t yet placed my finger on it, but I was suspicious of the “use compressed air to get rid of the dust in the memory bays” solution. So I placed the salvaged parts back into the ThinkCentre — having fun with which wires go where in order to make it work again — and got the four beeps again. I looked up what four beeps at start up means (here’s my archive of the table, which I had to recreate since a direct printing of the webpage only printed one of the tables,) and found that at least on a Lenovo ThinkCentre, it means “Clock error, timer on the system board does not work.” While I assumed that changing the BIOS battery may well fix the problem, I decided not to investigate any further.
I salvaged the parts again and placed them in my parts pile, ready for the next time I find a junker on the street or from elsewhere. The second ThinkCentre’s case was also placed beside the Dell, awaiting my next trip to an authorized disposal centre.
This means that out of the last three computers, I have one functioning computer replacing an existing computer (that I hope will continue with an industrious afterlife doing something else), one computer scavenged for spare parts and the case relegated to the disposal centre pile, and the Dell computer which was found on the street also relegated to the disposal centre pile.
Or, to paraphrase Meat Loaf, “One out of three ain’t bad …”
Cette page est principalement une place à exposer le lien pour ma présentation de ce soir au Linux Meetup Montréal au sujet d’utiliser le SSH et le SSHfs pour l’accès aux fichiers sur des autres systèmes depuis votre ordinateur linux (Fedora avec Gnome, dans mon cas).
Essentiellement, je discute le fait que SSH et SSHfs peuvent être utilisés pour les transferts des fichiers, et comment, à la base, les invoquer.
*****
This is a page to expose the link for my presentation this evening at the Linux Meetup Montreal discussing SSH and SSHfs for file transfers on other systems (Fedora with Gnome, in my case).
I started volunteering some of my extra computers’ idle time for the World Community Grid in December, 2013. Unfortunately, the machine in question, a used computer I’d bought about five years earlier and, after having been used as a desktop for a few years, had been converted to being a server under CentOS, died from a “thermal event” nine months later. It had completed 713 results and earned 419,591 points.
In 2016, I found a P4 3.4GHz machine, installed CentOS 7 on it, and then the BOINC infrastructure. I assigned it to the World Community Grid and 100% of its capacity to the project. From when it began in September, 2016 to today, it has completed 4,540 results, and earned 2,568,590 points.
In 2017, I finally converted my old netbook (32 bit atom processor) to CentOS 6 and did the same thing. From when it began in April until today, it has completed 261 results, and earned 133,073 points. (What a difference in capacity that 3.4GHz 64 bit has as compared to 1.6GHz 32 bit!)
Over the past few months, I have been collecting up a number of old machines which have come my way, including some IBM ThinkCentres from the Windows Vista era. So far, my brother and I haven’t been able to get them running properly, and we will probably end up using them for spare parts.
In the meantime, we acquired two more computers. My brother wanted / needed a replacement computer for his aging media server, an old reclaimed IBM ThinkCentre I’d gotten for him a few years ago. I, in the meantime, wanted to add another node to the World Community Grid (of course, working at 100% of capacity.)
I chose CentOS 7 for this build, like I did for my other nodes, for what I consider to be the obvious reason that I want to pretty much forget about the computers and just relish in the numbers on the World Community Grid website — I don’t want to be re-installing every year!
The install went well enough, although it was long enough process for the base install, as compared to my laptop and desktop. I will rule out the comparison to my laptop since the SSD and physical drive don’t compare at all. As for the desktop and node, I’ll chalk up the difference mainly to processor speed and general architectures: A 2015-era four core i5 running at 3.4GHZ vs a 2010 era Pentium dual-core E6500 running at 2.93GHz (no HyperThreading).
What was really long after that was the yum update after the initial install — about 650 packages! In the process of the updates, I tried a few things like web surfing, and the gnome desktop became unstable; I ended up with a flashing text screen. I finally rebooted, and tried to downgrade to an older kernel in GRUB, to no avail. I tried the rescue kernel, no avail. Under both situations, I couldn’t pull up a terminal with Alt-Ctrl-F2. A quick check under a Fedora live environment was a waste of time, since I didn’t really know how to diagnose things; however, I was able to mount the CentOS drive.
There was some flirting with the idea of installing Fedora 27, but I don’t want the re-installation mill on this machine (or any of my other volunteer computing nodes) every year — although, seeing my brother upgrade from Fedora 25 to 27 through the GUI go as smoothly as a routine DNF upgrade is making me wonder if the point is moot. (Note that CentOS 7, based on Fedora 19, is still using YUM, while Fedora has been using DNF since version 22.)
Finally, I restarted the install of CentOS, this time doing a minimal text install. Things were a touch faster. Then I did a yum update, with only about half as many packages to update. After that, I installed the Gnome Desktop on the machine. (Here’s my archive.)
I continued with the installation of the Fedora EPEL repository (as root “wget http://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm”, then “rpm -ivh epel-release-latest-7.noarch.rpm”). Installing the BOINC infrastructure was easy: As root “yum install boinc*”.
I launched the BOINC manager from one of the pull down menus, and, to my surprise, it actually worked out of the box, unlike previous installations. Someone must have updated the packages. 🙂 I added the World Community Grid website information, and my account and password.
Voilà! At 12:00 UTC the next morning, my machine had already submitted FIVE results, and earned 2,429 points! And, at 00:00 UTC as I’m completing this post, a total of EIGHT results, and 4,638 points!
Since about lat 2016, my website had problems with uptime: It was mostly down. In the spring of 2017, it was finally up and I did a bit of restoration work. And then … it was down again for a few months. (And, due to the circumstances of this downtime, my restoration work was lost.)
Finally, I transferred my website to an existing home server, and it is now living out of a computer which I believe may be as old as 2003, living under CentOS 7.x series, in my bedroom. Having fixed a faulty telephone line (squirrels!) the line is now “not noisy” and the internet is back properly.
Today I attended the ADTE Colloque 2016: The annual conference in Montreal (home for me) for a Quebec association with goals to promote free software in education.
Overall, the conference and its logistics were reasonably well organized; as far as the implementation of the event went, it seemed to go hitch free. Rooms that were appropriately sized were available, enough chairs were in place, there were no problems with the sign in, the microphones worked, the lunches arrived, and so on.
My interest was to see Richard Stallman, who was the keynote speaker.
Before he started his speech, I got to see his laptop almost closeup: He has a GNU sticker on it, an FSF sticker on it, and a small Trisquel sticker on it. I managed to ask him what the model was; an IBM Thinkpad X60, reconditioned, slightly upgraded, and marketed by a company called Gluglug.
Given that the conference was in French, Mr. Stallman presented what was no doubt his standard speech on free software, in French. (Let’s clear this up now: I’m a native English speaker, but Montreal is a predominantly French-speaking city; as such, since I live in Montreal, *of*course* I speak and understand French fluently.) Although I knew in advance that his French was competent enough to make his presentation in French, I was pleasantly surprised and very impressed that technically it was better than moderate in calibre, and that he could maintain it for over two hours with barely two or three requests to provide the French equivalent of a word or expression. And despite a fairly thick non-native speaker accent, it was almost surprisingly easy to follow.
His speech, although it appeared to be one of his standard speeches, went on too long in my view; 2.5 hours had been allotted for the presentation and questions, and I thought he could have accomplished the same thing in about 100 minutes, including questions.
I found that there were three downsides to his presentation:
– The “Church of Emacs” routine was off-topic or at least beyond the scope of the conference. Given what amounted to be a public audience, it was out of place. A cute parlour routine or pub talk in its own right, but out of place there.
– His comments about not having children were completely out of place, however legitimate they may be in their own right, and at best were poorly presented.
– Mr. Stallman apparently is losing his hearing, and asks people to speak a little more slowly, and clearly enunciate all their words. This is understandable, especially when those asking questions are not speaking his mother tongue; further, Quebec French and accents can be difficult even for native French speakers not accustomed to them. At one point, someone who forgot to speak extra clear and a bit more slowly elicited his ire as he either lost his temper, or whined like a child, repeating admittedly for the umpteenth time for the person to speak clearly and more slowly.
As for the rest of the conference:
The overall conference had a few quirks. The iPads at the registration desks were funny and out of place, given the topic of the conference. The glaring and blatant use of a Microsoft Windows computer on the overhead projector was a weird oversight to the point of being shocking, regardless of the fact that for all intents and purposes it ended up only being used to display the wifi network and password, and one minor demonstration during a roundtable discussion. This was addressed in the first question period by an irate participant who venomously commented on it and expressed his feeling of being insulted, to the applause of roughly at least a third if not half the participants.
For me, the first round table, before Mr. Stallman’s speech, left something to be desired. I thought that they could have been better organized instead of being just “I’m Tom Smith and this is what I do. Oh, and this is what I know about free software.”
The second round table, after Mr. Stallman’s presentation, was a bit meatier and not quite as disappointing as the first. There was an IT person who was trying to slowly provide Free Software by placing it in their pool of software available to staff at his institution, alongside other software. Another panelist provided a good and enlightening response to a question, to the order of “Try explaining *that* to a powerful teachers’ union!”
My brother said the comments then as well as elsewhere in the day felt like we were still in 2006 instead of 2016 given their nature, such as:
– “Well GNU/Linux is hard to install” (I found it easy to install in 2008, and installing other software and fixing settings is something one does on any platform);
– “LibreOffice isn’t fully compatible with MS Word” (that’s a very nuanced conversation that strictly speaking is technically correct, but mostly trivially, IMO);
– “I’m accustomed to program X”;
– “I didn’t know that you could do that using free software”.
The lunch included in the admission fee was fine albeit a bit too frou-frou for my tastes, and totally inedible for my brother’s admittedly very narrow tastes. I would have hoped that there might have been more than three or four tables in the trade show part of the conference, which was held in the large lunch room area, but that’s neither here nor there.
The two afternoon sessions I attended were on the subject of “Accessing the Moodle Community”, and the ProjectLibre software.
The first presentation on the Moodle Community seemed a bit off and probably confusing to most of the participants, being a bit obscure and technical. However, once I re-read the title in the day’s schedule, I realized that it *was* on topic (both for the conference, and, on topic for his presentation.) Disappointingly, the presenter was delayed by a good fifteen minutes, for technical reasons: He could not use his computer for his presentation, given that for some reason he was unable to plug it into the projector. He then tried to present his slides prepared in LibreOffice with a computer using MS Powerpoint, which did not like his slides. He finally had to install LibreOffice on the supplied computer which was effectively permanently connected to the projector, or the setup otherwise effectively precluded the use of his own computer. He should have been prepared with the slides saved in PDF format, but to his credit he had placed the presentation online so that he could access it easily, in addition to having brought it on his computer.
The second presentation was a bit better as it at least was a demo of free software that can be used by educators / schools / etc. to either to manage their projects, what kind of software can be taught in schools, etc.
However, I thought that the two individual presenters I saw had two failings beyond what I mentioned earlier about the Moodle presenter:
– They only had about half an hour each; they could have done with at least another 15 minutes each. Each went over their allotted time; in any case, they should have timed things better in their presentations given that they knew of their time limitations, or should have known, given the announcements online and in the printed schedules liberally distributed during the conference.
– They should have been coached in advance with “ok, present what you want the way you want, *BUT*, please spend the first up to five minutes answering these five questions, such as a brief description of what the software / project / topic is, what its use could mean to the participants, etc. etc. etc.” In addition, I thought that each unfortunately were unprepared for people asking questions and making comments during the presentations, which could have been handled with “Could you wait until I finish my presentation, at which point I’d love to take your questions and feedback.”
Overall, however, I did love participating in the conference.
In it are links to YouTube videos of Mr. Stallman’s presentation as well as a number of links to speakers’ quick resumé of what they spoke about to even sometimes slides of their presentations, again normally in French.
In 2011 a new hire at work was assigned to join me on a few field jobs in order to expose them to the kinds of things we do at the office.
At the time, I enthusiastically told him about my use of linux. Suffice it to say his reaction was “What is this communist stuff anyway?!?!” Harrrummmpphh. “Red Hat is in line to have $1 billion with a big fat capital B in revenues this year alone. Doesn’t sound very communist to me at all.”
Back in mid-December of 2015 — after countless times of telling him about linux in the meantime, hopefully a bit more toned down — he sent me a message: “Here’s a modest budget; set me up, I’d be interested in trying it out.” I was practically beside myself in my pleasure.
I came back from the Christmas holidays and announced that I’d tracked down a used computer for free, and just needed to get it into my hot little hands. I explained that I wanted to give him a relatively risk free introduction. In the meantime, the computer in question, I’m told, proved to be dead and not usable. I’m promised another computer, and this week, when it looks like I’ll indeed be getting it in time for an install day this weekend, I further explained to my colleague: “The computer is probably about four or five years old but it’s supposed to be a dual core with 4 gigs of memory. It won’t be the best performing computer in the world, and some things it just won’t be able to do, at least not spectacularly, not because of linux, but because of the computer itself; however, it should still be good enough for videos, games, and day to day stuff, and you’ll be able to explore all the software available for it and see what can be done with linux, and you can add a few things like a bluetooth dongle if you like.”
He cautiously tells me all along that I’m building up anticipation; the caution suggests to me that he is mildly tongue-in-cheek meaning “of the disappointing variety”.
I then start asking him very specific questions, like what he wants as the computer name (I give him examples of current and past computer names I’ve used, and advise him to choose carefully since using the name of a pet or relative could backfire in case something goes wrong, and in the process of relating the experience to family or friends they may be confused or even become upset), the user name and password to use, the root password he wants, and things like which email client he uses at home. Pleased that he’ll be able to use a GMail interface, he begins to apparently genuinely say “Oh now you’re *really* building anticipation!” instead of the cautious insinuations from before.
Therefore in anticipation of the build this coming weekend, I put together this list of the main things I’ll need to install on his computer, especially since I’ll be helping my brother-in-the-know again with another desktop install, and try to get in some of his under the hood expertise at getting my server to be a bit more useful than a rarely used ftp server, a backup server for my data which depends on my remembering to back up my data on it, and consuming electricity.
In Part I, I talked about installing Fedora 21 on a new Dell desktop, and promised a Part II, somewhat tongue-in-cheek. But wait folks, I was serious. 🙂
I have an Acer Aspire One which I received new out of the factory sealed box as a birthday present in 2009, and immediately converted it to linux after receiving it – Fedora 11, to be exact. It has used, as I recall, Fedora 11, 12, 14, 15, possibly 16, 17, and 19, all without any trouble. Well, ok, none that can’t be attributed to “whaddya expect out of a notebook vs. a full horsepower machine” and errors stemming from somewhere between the keyboard and the chair. ?
However, time is starting to march on with this machine, and while it was great under roughly 18 months of Fedora 19, it was clearly starting to slow down a bit, but … well, Fedora keeps releasing new versions, and, well, while CentOS 7, which is based on Fedora 19 and which I’d be happy to install on my netbook, unfortunately is only available under 64bit while my netbook is only 32bit. So my options were to either keep Fedora 19 unpatched, upgrade to Fedora 21 workstation, which I wanted to do, upgrade to Fedora 21 with XFCE, which would probably make it peppier, or explore other distros, which I don’t wish to do.
When Fedora 21 Workstation came out in December 2014, I downloaded the 32 bit version, and the fun began. Within a couple of minutes of booting up the live DVD and before the desktop loaded up, the machine went into hibernation. This didn’t feel right, but I hit a key and things came back to life. Then, within about a minute, the machine went into hibernation again. I hit a key again, got a minute of performance, and it hibernated again, ad nauseum, and ad infinitum, literally.
Despite this, I decided to continue with the F21 Workstation installation anyway, and I ended up babysitting the install, hitting a key to wake up the system every minute or so during the installation. On a single core atom processor running at 1.5 GHz, this took a good long while and a lot of keyboard wakeups. Finally, the system was installed, but it kept on hibernating after roughly a minute.
As a reference, I proceeded to install Fedora 21 XFCE Spin, and, except for hibernating once during the initial booting up of the liveDVD, it worked like a charm.
One solution I tried was to do a “yum install fedora-release-workstation” or somesuch from an installed XFCE spin, hoping to then do a “yum groupremove XFCE” and repeat “yum install fedora-release-workstation” just to reinstall any packages which may have gotten removed, but it bricked the install and I had to reinstall XFCE yet again.
For a variety of reasons which are now lost in the winds but which probably included having gone through the following suggestions from ask.fedoraproject.org, I managed to install and re-install the XFCE spin several times again after probably having reinstalled the Workstation a few times in between.
“You can do tests and get logs without interference with systemd-inhibit – ie sudo systemd-inhibit bash. The system won’t suspend or hibernate until you end the process invoked with systemd-inhibit.” This didn’t work; hibernation continued as before.
The next response was “I’m just guessing, but it feels like the system thinks that the battery is almost empty and because of that does the right thing in that situation. I’m not sure which software component is handling this situation but anyway, there seems to be a bug that happens to manifest on your particular environment.” This could have been ruled out immediately – mostly – because at the time the battery was physically out of the machine when I tested, and I was running on mains electricity out of the wall. Nonetheless, I did check, with a fully charged battery in, to be sure I wasn’t being a fool; no such luck, under both cases, the machine kept on hibernating every minute or so.
All through this, I learned that at least one user with a Toshiba Satellite Pro without a CD player had this same problem, and worked just fine up till Fedora 20.
“Try setting ‘HandleSuspendKey’ and ‘HandleLidSwitch’ to ignore in /etc/systemd/logind.conf” “Scimmia” further claims that this problem appears to be caused by systemd/logind. This all means that somewhere, signals are being sent out, rightly or wrongly or otherwise, that are being interpreted as “the clamshell lid is being closed, so it’s time to hibernate.”
To wit, my brother and I, after I’d installed Fedora 21 Workstation for the probably at least third time, then boot up an XFCE liveDVD (but do not install it), and through some of my brother’s linux kung-foo, he mounts the hard drive, using Thunar in the XFCE spin as a facilitator, and we edited the appropriate file.
… And Bingo was his name-OH. (Translation: Yup, that worked and the machine now works.)
Here are the instructions to correct the problem, at least for an Acer Aspire One, and which are also findable through ask.fedoraproject.org:
1) install F21 32bit workstation, by babysitting the system throughout the whole install to keep waking it up every minute or so (literally!)
2) reboot using a live-dvd that works on the system, such as the F21 XFCE live-DVD
3) mount the hard drive (not really sure specifically how my brother did it but using Thunar seemed to help out a lot)
4)open a terminal session and make sure the hard drive is mounted
5) edit the file /etc/systemd/logind.conf (such as using nano)
6) uncomment the settings for “HandleSuspendKey” and “HandleLidSwitch”
7) set the “HandleSuspendKey” and “HandleLidSwitch” options to “ignore”
8) save the file
9) reboot
10) enjoy
… and, it seems, my instructions, posted on ask.fedoraproject.org, helped at least one other user with an Acer Aspire one. I’m pleased. ?
Now, as for what I think of it … well I like F21 Workstation. On my laptop, it’s a slightly sluggish, but still working well.
I’d burned two live CD’s — one of the current Fedora of the day, and one of the current Ubuntu of the day. I had wanted a group I belonged to to use one to reformat a virus-infected computer to use it again. Incidentally, they declined the honour, however that’s beyond my point: I didn’t want to give them (or anyone) the Fedora CD, while I thought that the Ubuntu CD was great out of the box, specifically including OpenOffice.org (now LibreOffice) and a cute little directory including a short video, a sample mortgage calculator, and two or three other little gems which really put the CD over the top for its immediate usefulness.
Well, I haven’t really used Live CD’s much since I’m not all that worried about having linux on the run, but at this point Fedora 21 seems to only be available by Live CD’s. But to wit, the experience with Fedora 21 seems to be quite the improvement in experience, according to at least two of my somewhere between the stated and implicit standards of comparison: The inclusion of (now) LibreOffice, what I considered a killer omission, and the ability to quickly and easily install many “productive” pieces of software through the new software installer. To be fair, at the time Fedora limited itself to CD’s and in its efforts to include as wide a base as possible for supposed widest mass appeal, Fedora was unable to include OpenOffice.org (or, as possible, any usable subset thereof) due to space restrictions, although it was able to include AbiWord.
Now, Fedora Workstation includes LibreOffice, and by typing into the search box in the “Activities Overview” (click on “Activities” on the upper left hand corner of the screen, or invoke it using the “hot corner” by bringing your cursor up there), the installed software that may help you, as well as a number of other pieces of software in the repositories which may help you, as indicated by a little shopping bag to the left of the proposed piece of software.
Well, I guess now I just need to find someone who needs to have their computer saved from viruses and spyware. 🙂