GNU

I recently purchased a second-hand HP Proliant ML350p Gen8 in order to be used as a home server and to my disappointment realized I won’t be able to disable the hardware RAID that comes with this model, at least at first glance. Well, there is a way to do that, which is supported by HP themselves. And, this is how to do it the easy way!

But, before we proceed any further, you might ask why do I need to disable the hardware RAID? The answer is because I need to install ZFS. There is already plenty of documentation why installing ZFS on a hardware RAID is a terrible idea. Thus, I won’t go over that since it’s not the focus of this article.

Again, before we go any further there’s a catch you should know about. If you’d enable HBA-mode, the server won’t be able to boot from any disk connected in HBA mode to the controller! You should consider this before converting to HBA mode. In case you need to perform a FreeBSD/Linux root on ZFS installation through this controller there are two solutions:

1. Installing in hardware RAID mode, but making each disk a RAID-0 array consisting of only one disk. For example, if you’ve got 8 disks, you’ll end up with 8 RAID-0 arrays. Then you’d perform a ZFS installation and your operating system boots as expected. Though this is not recommended and if you’d proceed with this approach, it renders the rest of this post useless.

2. HP Proliant ML350p provides an SD-Card slot, which can be used to install a full system, which is not recommended due to the wear and tear effect of SDCards with each write-operation on them. In addition to that, this storage type is costly and slow. For example, a SanDisk SDXC Extreme Pro 256GB, which provides a write speed of 90MB/s and read speed of 170MB/s, costs around €99,99 where I live. With today’s standards, this is not fast at all or even good enough, especially on a server. I was also able to find a Sandisk CF Express Extreme Pro 512GB type B, with a write speed of 800MB/s and a read speed of 1500MB/s. It only costs €629,-, which costs an arm and leg to buy!

So, then! What’s the solution one might ask? We are going to install only /boot partition on the internal SD Card. Note, that placing only a bootloader such as GRUB, rEFInd or other similar tools won’t work as they won’t be able to see the boot drive anyway! So, the only solution is to put the boot partition on the SDCard. This way, the system only reads it one time at boot and it does not even have to be an expensive SD-Card.

So, let’s begin!

UPDATE [2021/11/08]: For whitelisting macOS, one could simply add Mac to PlatformAllowList inside the .uplugin file. e.g.:

	"Modules": [
		{
			"Name": "ModelingToolsEditorMode",
			"Type": "Editor",
			"LoadingPhase": "Default",
			"PlatformAllowList": [ "Win64", "Linux", "Mac" ]
		}
	],

I’ve been trying to enable and make use of UE5’s Modeling Tools Editor Mode Plugin inside the editor built from ue5-main and 5.0 and struggled to some extent. According to Epic Games, this should suffice:

If you are starting up a new project, the modeling mode plugin may need to be turned on. From the Plugins window, enable the Modeling Tools Editor Mode Plugin and restart Unreal Engine.

So, I did enable the plugin from inside the editor:

To no avail and I was never able to find it inside the UE5 editor:

Despite that, I was able to figure out what’s wrong. Here’s how I fixed it on Linux and it’s an easy fix. It probably works on macOS, too. Though I have no idea why Epic Games has disabled it on non-Windows platforms in spite of the fact that it works just fine.

A few months back due to various changes in how Funtoo is being managed, I migrated back from Funtoo to Gentoo after almost a decade. After some time I realized my laptop randomly gets stuck on a blank screen and freezes just right before my login manager (SDDM) starts. I noticed the hard-disk LED is blinking and the system is actually not freezed and probably is working and stuck on something. Checking the system or Xorg logs did not reveal anything unusual.

I even posted my issue on the Gentoo Forums and when I thought the issue is gone I marked it as SOLVED (well, I don’t turn off this laptop or reboot too much). But, the problem came back and hunted me over again.

Finally, I decided to install JuiceSSH on my phone since I do not have access to another PC for the time being. When it did freeze, I did ssh into my Gentoo installation and noticed udevd’s CPU usage is at 100%. I looked up the forums to see if someone else having this issue or not. I cannot recall where on the forums I saw it, but it seems this was a known issue to some users with recent NVIDIA drivers and someone suggested blacklisting the NVIDIA drivers, so the kernel won’t load them at boot time as it is going to be loaded by X later on.

Well, I did the following changes in order to blacklist the NVIDIA modules, so the kernel won’t load them at boot itme:

blacklist nvidia
blacklist nvidia_drm
blacklist nvidia_modeset
blacklist nvidia_uvm

And, viola! It has been a month without any issues so far. It did solve the issue for me, once and for all. Hope it helps someone with a similar issue until this bug is officially fixed.

Update [2019/05/08]: Many people have been asking for the wallpaper in the above screenshot. It is from System Failure II, oil on canvas, 31x43” on r/Art.

Well, I am really fascinated by Reddit art and genuine creative ideas such as Scrolller which was made possible thanks to gazillions of art pieces scattered throughout various art subreddits. I am also fascinated by Unix philosophy and have been a *nix enthusiast for as long as I can remember. In addition to all this, the discovery of r/unixporn - realizing I am not the only one who cares about aesthetics of their Unix box - was a huge blow for me; to the point that studying the GitHub dotfiles posted along the screenshots on r/unixporn by fellow nix-enthusiast redditors felt like a day to day hubby for me.

All the while, I had a successful experiment with writing a complex piece of real-world software in pure Bash with an amazingly wide range of features for around 3.5K lines of code. The real excitement came when it made to the official FreeBSD Ports Tree. In spite of the fact that many people find Bash syntax annoyingly ugly and unmaintainable and often wonder why do people still write shell scripts by asking it on Quora, since MS-DOS 6.22 era, I did develop a certain love–hate relationship with shell scripting languages such as Batch Files, Bash, etc. Thus, still I do automate almost everything with these ancient technologies.

So, here is my fully-configurable wallpaper changer software written in bash which automagically fetches and display wallpapers from your favorite subs. It has been powering and brightening up my i3wm setup for the past eight months which led me to the conclusion that it deserves a proper introduction.

Well, I haven’t played a multiplayer game in ages until recently, when my cool boss announced regular playtimes for all the employees in our company as a group activity in order to put the fun back into work. Since I’m a die-hard COD4 fan and I used to play Promod LIVE heavily with colleagues and friends, I proposed Call of Duty 4: Promod LIVE 220 which happened to be favored by everybody; except there was one issue: everyone uses Microsoft Windows while I’m developing UE4 games on a single-boot Funtoo Linux system.

Naturally, my first attempt was running it inside a Windows 7 virtual machine under VMWare Workstation for Linux which supports up to Direct3D 10 (the exact API used by COD4). Sadly, the experience was very poor and painful with lots of unbearable stuttering on my decent hardware. Thus, the last resort was running it under Wine, which I used to happily run many Windows applications and games under it for many years. Though, throughout those years I replaced almost every Windows application with an equivalent or an alternative Linux application until I gradually stopped using it. In the meanwhile, I also distanced myself from traditional desktop environments such as GNOME, KDE, Xfce, and LXDE, while experimenting with various window managers specially i3wm, which caught my attention for many good reasons. So, in the end I made up my mind and alienated myself from desktop environments once and for all.

Running a fully-fledged game engine such as Unreal Engine 4, I expected COD4, Wine, and i3 combination to work fine out of the box as it would under any other DE. Well, it turned out that I was too simple-minded about running a fullscreen game such as COD4 under Wine/i3wm. Hopefully, as the Wine FAQ states the workaround is super easy.

Here is the full guide on running COD4 v1.7 with Promod LIVE 2.20 on GNU/Linux.

Update 1 [2016/09/30]: A section has been added to the end of the article for dealing with major FreeBSD upgrades.

Update 2 [2016/09/30]: A section has been added to the end of the article for upgrading current installation of Discourse to newer versions.

Update 3 [2016/09/30]: A section has been added to the end of the article for installing Discourse under Ruby version managers which is required for dealing with newer versions of Discourse since the current system-wide version of Ruby on FreeBSD is 2.2.5p319.

Update 4 [2016/10/06]: I decided to get rid of Discourse on this blog for various reasons including negative feedback from my readers, performance issues, being a memory hog and not so easy on memory, difficult maintenance, dealing with building Ruby Gems which is a tedious task in case they fail to build and a bug that duplicates my posts and creates a new thread for each post which means it won’t show previous comments. Last but not least, in my estimation it’s too heavy for such a small task such as a comment system. As a result, this guide won’t be maintained anymore.

Well, when it comes to blog comment hosting services for static blogs, you will have a plethora of options such as SolidOpinion, Disqus, Livefyre, Google+ or Facebook comments, and many more. Unfortunately, such services has never been an option for me and I resisted them like forever. Yes, I’ve got one million reasons to believe and do so which demands another post of its own. So, I’ll avoid that argument for now.

This left me with two choices:

• Operate my blogs without the comment section as I did for years
• Running an open source self-host blog comment system such as HashOver, Isso, Juvia and talkatv

Since people asked me for a way to discuss their feedback on the website, this made the former choice a no go, anymore. So, in a search for the promised commenting system, I spent hours installing and trying every single FLOSS commenting system on GitHub. And everyone of them has had a big flaw that I could not tolerate. Finally, I came to the conclusion that I’m out of luck with that. Of course, I always had the option to write my own commenting system according to my own needs. As, I did with my own blog subscription system. But, due to the lack of time that was not an option either.

It happens that I randomly visit Coding Horror by Jeff Atwood the co-founder of Stack Overflow and Stack Exchange Network. I’ve always read the comments on Coding Horror but never had an urge to write a comment their. Since I’ve been desperately looking for a commenting system, this time the different look of its comment system catched my attention. Bingo! He wrote an open source discussion platform software named Discourse. Not necessarily a blog comment system, but could be used as one. It even supports the Farsi language and RTL out of the box which allows me to use it on my Farsi blog, too. In addition to that it supports multi-site which means I have to only run one instance for all my blogs. Just perfect!

Despite many nice feature it provides, it has a few rough edges, too. I was able to conquer some and some couldn’t, yet. But it did not stop me from integrating it into my Hexo-based blogs after two weeks of testing it. So, there it is, from now on both this blog and my Farsi blog are discussion aware :).

OK, the main issue that many people face when they want to install Discourse in a platform other than GNU/Linux, is they get hit in the face by the reading this line in the official documentation:

Why do you only officially support Docker?

Hosting Rails applications is complicated. Even if you already have Postgres, Redis and Ruby installed on your server, you still need to worry about running and monitoring your Sidekiq and Rails processes. Additionally, our Docker install comes bundled with a web-based GUI that makes upgrading to new versions of Discourse as easy as clicking a button.

Yes, I know Ruby and Rails are crap and deploying Ruby on Rails apps are pain in the Butt. Do not worry! This was the first struggle with Discourse that I had since this blog runs on FreeBSD. And, FreeBSD support for Docker is experimental, yet. Fortunately, I used to deploy GitLab instances on FreeBSD for three years which was also RoR before I migrated to Gogs which kicks butt, anyway! That made it easy to figure out a simple way to deploy Discourse without Docker on FreeBSD.

Undeniably, flaming has been around since the dawn of the Internet age. And even worse, it has been on the rise ever since. Gazillions of flame wars on websites such as Slashdot or Reddit surely is enough proof, the greatest of which is the perennial debates between users of competing operating systems.

No doubt I’m a FLOSS enthusiast and advocate who considers free/libre/azad software superior to the proprietary ones, by all means possible. But like all software, the FLOSS ones have some shortcomings, too. So, the point is no one-hundred percent reliable software exists on this planet which means open source software may also suffer from bugs or security flaws as proprietary software do.

Today is Linux kernel birthday and many FLOSS enthusiast and advocates around the globe are going to celebrate it. I’m a diehard FreeBSD fan, but it won’t stop me from celebrating Linux birthday. In fact, I still use GNU/Linux for building native C/C++ libraries using Android NDK on a Slackware machine. In addition to that, I used to be a heavy Funtoo / Gentoo user. The thing is, I appreciate the tools I use, no matter what. So, I’m going to celebrate Linux birthday by telling you a story. A story that made an unforgettable trip even more memorable. Here’s the story of a GNU/Linux system in production which crashed in its hometown, Helsinki, Finland.

Update 1 [2016/09/23]: OmniBackup now officially supports GNU/Linux. More info…

Update 2 [2016/09/23]: Official documentation moved to GitHub which means this guide won’t be maintained anymore and maybe out of date or inaccurate.

A week ago was System Administrator Appreciation Day. It is celebrated on the last Friday in July and it has been celebrated since July 28, 2000. But, system administrators know not all days are like that day. They face many hard times and struggles during their careers and the worse of them all is either a security breech or data loss.

For so many years I’ve been writing and maintaining backup scripts on and on, for every single database I added, for every single directory with critical data, or any other service I was running on every new server I got my hands on. In the end, I found myself ended up in a pile of backup scripts and multitudinous cron entries which was a nightmare to keep track of. I even had to manage the schedule so that two backup scripts do not run at the same time. Even more, I had to manually track the backups to see whether they were successful or not. Also, someone has to manually delete the old ones to make rooms for the next ones.

Therefore, I came up with an elegant solution to replace the old process which I found exceptionally error-prone. An end to all my hardships which I call OmniBackup. At last, I’m able to confidently keep abreast of all the ever-growing data that I have to keep safe.

“So, what exactly is OmniBackup?” you may ask. “A fair question,” I would say. OmniBackup is a MIT licensed Bash script which delivers the following set of features:

• Configuration and customization of backup mechanism through JSON
• Support for OpenLDAP backups
• Support for PostgreSQL backups as a whole or per database
• Support for MariaDB and MySQL backups as a whole or per database
• Support for filesystem backups with optional ability to follow symbolic links
• Support for pluggable customized scripts to extend OmniBackup functionality beyond its original design which allows support for many different backup scenarios that has not been built into OmniBackup, yet
• Backup file name tagging which allows including date or host name in the archive name
• Online backup without a prerequisite to suspend any service
• Support for customized backup tasks priority order
• Support for multiple backup servers
• Ability to always keep a copy of backups offline
• Ability to keep a copy of backups offline if no backup server is available, or in case of an error such as a file transfer error
• Secure file transfer through SSH / SCP protocol
• LZMA2, gzip and bzip2 compression algorithms along with different compression levels to maintain a balance between speed and file size
• Ability to preserve permissions inside backup files
• Support for symmetric cryptography algorithms AES-128, AES-192 and AES-256 (a.k.a Rijndael or Advanced Encryption Standard)
• Random passphrase generation for encrypted backups with variable length and patterns or a unique passphrase for all backups
• Support for RSA signatures to verify the backup origin and integrity
• Passphrase encryption using RSA public keys for individual backup servers
• Backup integrity verification by offering hash algorithms such as MD4, MD5, MDC-2, RIPEMD160, SHA, SHA-1, SHA-224, SHA-256, SHA-384, SHA-512 and WHIRLPOOL
• Optional Base64 encoding
• System logs and a standalone log file including all details
• Reporting through email to a list of recipients with ability to include passphrases
• Customized mail subject for successful and failed backup operations
• Customized support message for reports
• Crontab integration
• Custom temporary / working directory
• Automatic and smart clean-up ability
• One instance only policy which avoids running multiple instances by mistake at the same time, therefore avoids system slow-down
• An example configuration file in JSON format to get you up and running

There is also a list of planned features and TODOs which did not make it into 0.1.0 release:

• Restore script
• GnuPG integration
• SFTP and FTP support
• Refactoring and code clean-up
• Any potential bug fixes

Disclaimer: Please be wary of the fact that this script has approximately 3.5 K lines of Bash code and devoured hell of a time from me to write and debug. You should also consider that this is my first heavy Bash experiment and I may not write quality code in the language since I’m a newcomer to Bash. I do not claim that OmniBackup is production ready, that’s why I did version the first release at 0.1.0. Also keep in mind that OmniBackup heavily relies on 3rd-party software which increases the chance for fatal bugs, therefore losing data. So, I provide OmniBackup without any warranties, guarantees or conditions, of any kind and I accept no liability or responsibility for any misuse or damage. Please use it at your own risk and remember you are solely responsible for any resulting damage or data loss.

Credits: Many thanks go to my fellow and long-time friend, Morteza Sabetraftar for his help and ideas without whom OmniBackup lacked features or quality. Another kudos goes to my brother Amir by releasing me from shopping, cooking and house-cleaning without even mentioning it, an invaluable and priceless assistance that encouraged me even more to use my best endeavours to get this task done.

Please, feel free to clone and modify it as you wish. Pull requests for new features, improvements or bug fixes are also very welcome.

• OmniBackup on GitLab
• OmniBackup on GitHub

The rest of this post serves as a comprehensive guide on how to setup OmniBackup in order to backup and restore all your critical data in a production environment.