LWN: Comments on "OpenSUSE considers dropping reiserfs"

Removal of filesystem support: downsides

landley — Sun, 04 Sep 2022 17:46:29 +0000

Just use a VM to boot an old OS image. Knoppix and friends have booted from ISO since 2000.

Even if conversion is only supported for ~7 years or so, you can boot an image from within that timeframe, convert the data to the newer archive format, boot the NEXT one you need a decade later, convert to the next format, etc. On any unixoid you can almost always manage to write a tarball to an NFS mount, or pipe it through uuencode to an emulated serial device being written to a file, or some such.

Storage getting bigger makes old block devices easier to image, and a proper data recovery setup will have snapshots of things like the devuan "pool1.iso" file so the servers having gone away no longer matter even if you need a weird obscure tool out of the repository:
https://ftp.nluug.nl/pub/os/Linux/distr/devuan/devuan_chi...

And you can usually dig up really _old_ stuff if you know where to look... https://archive.download.redhat.com/pub/redhat/linux/

OpenSUSE considers dropping reiserfs

roblucid — Sat, 20 Aug 2022 21:33:25 +0000

I maintained the UNIX habit of a small seperate /boot fs, usually ext2 to avoid such issues.
After running a lot of machines you get defensive from seeing file corruption in / and try to eliminate dramas.

OpenSUSE considers dropping reiserfs

roblucid — Sat, 20 Aug 2022 21:20:49 +0000

Well that happened but reiserfs had been the default in SuSE, I remember changing to ext4 for the system fs and the distro announcing that reiserfs was no longer possible to support.

OpenSUSE considers dropping reiserfs

roblucid — Sat, 20 Aug 2022 21:13:01 +0000

OpenSuSE basically deprecated it a very long time ago, announcing it couldn't be supported in future, IIRC that was the release when ext4 was included and the default.
I remember as I used reiserfs in SuSE since the release with 2.4 came out, later with XFS which was the one that gave me trouble with corruption on power failures until I bought a UPS.

OpenSUSE considers dropping reiserfs

zdzichu — Tue, 16 Aug 2022 16:22:13 +0000

Why would he? It's illogical.

OpenSUSE considers dropping reiserfs

tome — Tue, 16 Aug 2022 14:39:33 +0000

> what it does, in effect, is give the _chance_ that he could be let out earlier

that generally requires remorse, of which Reiser has none

OpenSUSE considers dropping reiserfs

jem — Sat, 13 Aug 2022 08:31:49 +0000

>Me, roughly one month ago when I discovered the hard way that ext4 is not made for many files

It is generally a bad idea to put a huge amount of files in a single directory, no matter what filesystem you are using. You'll run into limits and performance issues. Fortunately, there is a simple solution to this: design your app to spread the files into subdirectories, like Git does.

OpenSUSE considers dropping reiserfs

k8to — Fri, 12 Aug 2022 18:44:47 +0000

Yeah, reiser was pretty good for a usenet server around 2000, but I think xfs became the standard choice for this type of scenario not that long after. Good luck with your workload.

OpenSUSE considers dropping reiserfs

Conan_Kudo — Thu, 11 Aug 2022 15:08:33 +0000

It is also possible to convert from ReiserFS to Btrfs in-place.

OpenSUSE considers dropping reiserfs

smurf — Thu, 11 Aug 2022 13:35:27 +0000

You can do an in-place conversion from extfs to btrfs, though.

OpenSUSE considers dropping reiserfs

kena — Thu, 11 Aug 2022 03:42:56 +0000

This was gone into some detail at the time of conviction, as many people thought he was getting a sweet deal. Turns out that "15 years to life" can very much mean "to life," as the circumstances -- he proved he'd killed her by immediately locating her body -- were pretty damning. So what it does, in effect, is give the _chance_ that he could be let out earlier, but it's very likely he'll spend several more decades, if not his entire life, behind bars.

OpenSUSE considers dropping reiserfs

hailfinger — Tue, 09 Aug 2022 20:24:56 +0000

Me, roughly one month ago when I discovered the hard way that ext4 is not made for many files. Yes, you can use tune2fs at runtime to raise the file limit per directory (large_dir option), but there is no way to undo that except throwing the filesystem away and recreating it from scratch.
GRUB won't boot from an ext4 filesystem with large_dir active, so I suddenly had a non-bootable system with no spare capacity to recreate a working state. Lesson learned.

Then I remembered that ReiserFS (which I had used many years ago when it was more stable than ext3) has no inodes and thus no inode limit. And there are tools to do an in-place conversion to ReiserFS. However, the looming deprecation of ReiserFS and its non-maintenance seem to have accumulated bugs slightly faster than ext4 where bugs are introduced through maintenance (b5776e7). So... ReiserFS was not a choice anymore.

In the end I chose XFS and recreated everything from scratch.

OpenSUSE considers dropping reiserfs

swilmet — Tue, 09 Aug 2022 12:01:52 +0000

For old disks kept as archives (not necessarily powered-on all the time in a cloud).

For files that you don't need anymore but you prefer to keep as backup (for 10 years or 20 years), a practice is to have two disks with the same content, but disconnected. From time to time, you may check that the content is still readable.

That way it uses less energy.

Removal of filesystem support: downsides

nybble41 — Tue, 09 Aug 2022 02:11:35 +0000

There is a ready-made tool for exactly that: https://libguestfs.org/guestmount.1.html

Removal of filesystem support: downsides

k8to — Tue, 09 Aug 2022 01:30:01 +0000

I'm no expert, but i would think that passing a block device from a hardware kernel along to a vm kernel that deals with the filesystem shouldn't be that hard, in the worst case.

Removal of filesystem support: downsides

plugwash — Mon, 08 Aug 2022 23:13:20 +0000

While it's cool that grub does that, I would have a couple of concerns.

1. How robust are the grub drivers? have they ever been tested in any context other than booting a system?
2. Will grub continue to support filesystems if/when they are dropped from the kernel.

Removal of filesystem support: downsides

willy — Mon, 08 Aug 2022 20:37:45 +0000

If you read the linked email ...

> If these are in active use, I would seriously encourage migrating to something actively maintained. If these are sitting on a shelf for archival purposes, GRUB ships with a fuse frontend for all of its file system drivers, including reiserfs. It's not fast but it's enough for data access.

Removal of filesystem support: downsides

chris_se — Mon, 08 Aug 2022 20:18:53 +0000

I don't have any current storage that uses reiserfs, and I don't think that you should still be using it in production systems today. But what happens if at a later point in time one still finds an old drive (or even image file) that contains reiserfs. It would be great if there was some kind of support for at least reading these devices, so that data stored on them is not lost simply because the fs is outdated.

This argument is not reiserfs-specific, in general this applies to any existing filesystem that that the kernel has either already dropped or for which there are plans to drop it at some point in the future.

This doesn't have to be in the kernel: a FUSE-based project that gathers all filesystems removed from the kernel and provides read-only support for accessing them would be plenty sufficient. Doesn't have to be very fast, doesn't have to provide write support, just has to work, so that when one encounters a device somewhere with such a filesystem, one can still access the data stored on it. Does anybody know of such efforts?

OpenSUSE considers dropping reiserfs

jeffm — Mon, 08 Aug 2022 17:43:40 +0000

We don't consider it first-class. In SLE15, it's only been supported in read-only mode as a migration path and we don't ship the tools for it.

OpenSUSE considers dropping reiserfs

Matlib — Mon, 08 Aug 2022 15:58:55 +0000

Yes, kernel 4.x.x and reiser3.

OpenSUSE considers dropping reiserfs

gwolf — Mon, 08 Aug 2022 14:15:21 +0000

Although ReiserFS does carry its creator's last name, and he was the ultimate authority on its workings... Don't expect him to run back to coding (with as great skills as he had back in 2008) as soon as (and of course, if) he gets out. Also, the kernel today is not the same as the kernel 15 years ago. We should all accept ReiserFS had some neat ideas, but its time has gone, and it should be removed — probably in stages (first from the distributions, later from the kernel). It is not _that_ hard to move over to a different FS (given a multi-year timespan).

OpenSUSE considers dropping reiserfs

IanKelling — Mon, 08 Aug 2022 13:59:26 +0000

I'm not an expert, but afaik, 15 years to life in the US is generally considered a life sentence; only a small percentage get out.

It sounds like this removal is a good thing.

OpenSUSE considers dropping reiserfs

rsidd — Mon, 08 Aug 2022 08:34:06 +0000

Yes, and Reiser was sentenced in 2008 to "15 years to life", so he may be released in 2023 (I'm not sure how it works).

In my opinion ReiserFS users should have made their migration plans in 2008 (and SuSE should have deprecated it at that time). Almost all hardware from that time must have been upgraded long ago; they should have avoided ReiserFS on any new machine. Reiser himself was already deprecating it in favour of Reiser4, and it was all practically a one-man show.

OpenSUSE considers dropping reiserfs

donbarry — Mon, 08 Aug 2022 06:42:31 +0000

A sense of the timescale on which the kernel retains features is that Hans Reiser has already come up for one parole hearing, denied in 2020, and will have another one in early 2023. He's currently in a special prison that provides for medical needs, including mental health needs, which is perhaps unsurprising.

OpenSUSE considers dropping reiserfs

developer122 — Mon, 08 Aug 2022 03:39:00 +0000

I think he means kernel 4.0

OpenSUSE considers dropping reiserfs

motk — Mon, 08 Aug 2022 03:20:55 +0000

Who in glub's name is still using this in 2022, what the actual etc.

OpenSUSE considers dropping reiserfs

k8to — Mon, 08 Aug 2022 00:36:23 +0000

resier 4 has been dead for some time. reiser3 is the thing that's in the kernel and mostly works.

OpenSUSE considers dropping reiserfs

Matlib — Sun, 07 Aug 2022 23:25:47 +0000

It's been broken since 4.0 with some severe bugs. It used to be my weapon of choice for laptops, VMs and embedded stuff, and if fact I'm stuck with the last long-term kernel 3.x.x on one such machine.

OpenSUSE considers dropping reiserfs

randomguy3 — Sun, 07 Aug 2022 21:16:57 +0000

a follow-up to that email notes that it is planned to be removed from the kernel in 2025

OpenSUSE considers dropping reiserfs

Wol — Sun, 07 Aug 2022 20:38:00 +0000

Reiserfs was only ever really supported by SuSE, I believe ...

SUSE would have nack'd removing it from the kernel, but Tumbleweed dropping it probably is signalling quite clearly that its days are numbered ...

Cheers,
Wol

OpenSUSE considers dropping reiserfs

flussence — Sun, 07 Aug 2022 20:30:49 +0000

Weren't there proposals to remove it from the *kernel* last year or so? I'm surprised they still claim first-class support for it.