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Is it time to remove reiserfs?

by thestoicattack on 2/23/22, 2:44 PM with 244 comments

• by cestith on 2/23/22, 3:21 PM

  Personally I've always really liked ReiserFS. The collected storage of small files, the storage of the tails of files, the balanced tree structure, and the fast journaling gave better performance in reads, writes, boot time, and storage efficiency than most file systems. The focus on small files, which were and arguably still are most files on a typical system, was a big key to this. It made it ideal for storing things like configuration files, email in maildir format, email spools, version control repositories, source directories, and many executables. The logical successor was supposed to be btrfs, but that project IMHO may never be ready for production use.

  All that said, if it's hurting kernel development and almost nobody is using it, perhaps a deprecation cycle is due. Maybe bcachefs is a good replacement? Or perhaps nobody cares about efficiently storing small files these days at all, and we just all go to XFS, ext4, and ZFS. I think dropping it during a short period is detrimental to users. Maybe a two or three version warning is due.

• by marginalia_nu on 2/23/22, 3:08 PM

  ReiserFS does have its benefits in highly specific use-cases.

  I have a filesystem with an absurd number of tiny files in it. I host a statically rendered wikipedia mirror. Tens of millions of gzipped html-files with a filesize in the range 1-5 Kb.

  ReiserFS is the only filesystem I know that deals even the slightest bit gracefully with this thanks to tail-packing.

• by codazoda on 2/23/22, 3:20 PM

  > NB: Please don't discuss the personalities involved.

  Ah, but that's all I can think about when I read about reiserfs. For anyone who is unaware, the author, Hans Reiser, killed his wife and hid her body. There was a long and public investigation and he was found guilty. He later produced her body as part of a plea deal.

• by shaky-carrousel on 2/23/22, 3:30 PM

  > There don't seem to be any fixes for user-spotted bugs since 2019. Does reiserfs still have a large install base that is just very happy with an old stable filesystem? Or have all its users migrated to new and exciting filesystems with active feature development?

  Data loss bugs sure sound exciting, but I'm old, and stable, and I prefer my file systems like myself.

• by Frost1x on 2/23/22, 3:19 PM

  ReiserFS is a conversational litmus test I like to casually and indirectly name drop in technical interview discussions surrounding the world of Linux, file systems, and storage to fish and see if someone actually had been actively working in the domain circa 2000ish when there was a lot of hype and criticism bubbling surrounding performance with large sets of small files.

  Admittedly, it's not a great signal if the candidate hadn't heard of it or used it depending on their career length because plenty avoided it and happily lived in other FS worlds or avoided certain hype, but it's a fairly good positive signal if someone actually starts talking about it knowledgably in some way regardless of it on positive or critical notes--just have to keep survivorship and confirmation biases actively in mind when weighing these things.

• by madphilosopher on 2/23/22, 3:36 PM

  ReiserFS is my favourite Linux filesystem. I use it where most people just use the default ext4. I was originally attracted to it for the large-number-of-small-files support it had.

  I appreciate the ability to shrink/grow an existing ReiserFS, which I do often enough as I add new storage to my LVM layouts.

  I have never lost a ReiserFS filesystem due to corruption, so the tooling seems sufficient for me.

  I hope it stays in the kernel for a long time.

• by DocTomoe on 2/23/22, 3:16 PM

  ReiserFS is a lesson in project naming.

  When I started in Linux full-time, back in the early 2000s, I was presented with different fs options - the installer did not give me any information on benefits, or on which ones were considered "stable". ext2 was available, but it also had a built-in version number, and I feared that once ext3 eventually rolled over, it might be incompatible. So I chose the fs that came with a name attached: ReiserFS. If someone was willing to attach their name to their code, I figured, that must be some quality code.

  ReiserFS served me well, even though it always was a system lurking in the background. I was not a storage specialist. I was just a guy doing work on a Linux desktop, and ReiserFS "just worked". Occassionally, I put in a new disk, and watched the progression of other fs. Eventually, I switched over to ReiserFSv4.

  Fast forward a few years, and the whole murder thing happens. Immediately the thing that made ReiserFS stand out for me becomes radioactive - the name is burnt. And I see distros slowly phasing out advertising the option of having a ReiserFS partition. Yes, it was still there when you searched for it, but it didn't feature prominently in the installers anymore. And it is obvious that the code becomes stale - arguably understandable, who would do OSS work on code that is branded the name of a murderer?

  Twenty years later, I am still a Linux user. The last ReiserFS disk got shredded a year ago. Feels like the end of an era.

  Lessons learned: Naming matters. If you attach your name to something and want that project to survive, maybe do not commit violent crimes.

• by fest on 2/23/22, 3:35 PM

  What other filesystems have checksums for data? Last time I looked, after a silent SSD failure that I only noticed because some .so files were affected, the only options were btrfs and reiserfs (I think ZFS required a custom kernel at that time).

  The incident was really eye-opening in how fragile was my data: if .so files were not affected, I would have continued to use the system and erroneous data would silently be propagated to backups.

• by indymike on 2/23/22, 3:27 PM

  ReiserFS has been stable for a long time, and especially useful for spinning metal disks that need to store lots and lots of small files. Not sure that there is a modern replacement that will be able to do this well.

• by Andrew_nenakhov on 2/23/22, 4:18 PM

  I, for one, don't understand why can't they give Hans a computer and an internet connection and allow him to work on some open-source project.

• by tombert on 2/23/22, 3:30 PM

  Maybe someone with more understanding of kernel development could explain things to me.

  Does there have to be explicit kernel-level support to support a filesystem? Even if they remove support, does that stop anyone from releasing a kernel module and supporting it?

• by captainmuon on 2/23/22, 3:34 PM

  I wonder, how does the principle of not breaking userspace mesh with removing of file systems or drivers?

  I think some of the published cases where userspace would have been "broken" and Linus got angry were fairly minor, as in you might not even need to fix the software, the user just has to be aware of different defaults. Whereas updating a kernel to a version where the filesystem is not supported will definitely render the installation unusable.

• by debug-desperado on 2/23/22, 6:03 PM

  According to wikipedia Hans might be out on parole next year. As part of his release agreement he should be required to maintain his namesake filesystem.

• by joecool1029 on 2/23/22, 11:03 PM

  Can we just swap it for reiser4/5? It's only got a few people working on it but the FS is faster, has a plugin system for compression and other features, and is all-around just better. Call it shiskinfs if the name is problematic.

  If paragon can get their cribbed together ntfs driver included in mainline then why can't reiser4 get merged?

• by anxrn on 2/23/22, 3:06 PM

  I presume by personality they're referring to Hans Reiser, the creator of ReiserFS, also a convicted murderer.

  Past HN thread: https://news.ycombinator.com/item?id=2131221

• by bjourne on 2/23/22, 4:13 PM

  Implicit in Wilcox e-mail is the claim that there is a non-trivial cost of keeping reiserfs even when it is not being updated. Cost of keeping resierfs in the kernel > Cost of removing it. A filesystem is like a plugin for the kernel. In theory, it doesn't care what filesystem you use because it only access it using a common plugin interface. So keeping reiserfs in the kernel should cost 0. In practice, the cost is higher. Young developers often don't understand that. Plugins, extensions, modules, backends, what have you, no matter how great the extension mechanism is, you can't completely eliminate the costs.

• by jordigh on 2/23/22, 3:44 PM

  "WE DO NOT BREAK USERSPACE"

  https://lkml.org/lkml/2012/12/23/75

  I was surprised to see that Linux has in fact removed other filesystems in the past (and I had to look up the word "senescent").

  So the real news to me here is that a somewhat "major" break in userspace is being considered.

  Sure, ReiserFS might not be getting a lot of new installs, but the fact that people have submitted fixes to it within the past few years means it has some. There are installs of it out there. Wilcox is considering breaking userspace for some users.

  Linux is famous, famous for keeping backwards compatibility for almost everything forever. The stories of Linux backwards compat are up there with stories of Windows still supporting AUX and CON and other special file names. Is "WE DO NOT BREAK USERSPACE" still worthy enough to be shouted at the top of your email lungs?