On 2017-09-20 12:55, Dave Howorth wrote:
On Wed, 20 Sep 2017 08:39:56 +0200 Richard Brown <RBrownCCB@opensuse.org> wrote:
On 20 September 2017 at 08:22, John Andersen <jsamyth@gmail.com> wrote:
It was a jab at Brown's denigration of Reiserfs simply because it's mature and needs no maintenance.
Apart from the fact that ReiserFSv3 is the only filesystem I am aware of who's fsck consistently destroys data?
OK, there's a bold assertion and I see there's some justification following, so lets approach this claim with an open mind ...
If you store a ReiserFS v3 disk image (VM, container, etc) on a ReiserFS v3 filesystem, fsck WILL confuse your the disk image for another partition and 'restore' files from the image, corrupting the filesystem and losing data in the process.
OK, so don't do that then! Not something I'm likely to want to do. Moving on ...
The wikipedia explains the issue much better. https://en.wikipedia.org/wiki/ReiserFS First: «Namesys considered ReiserFS (now occasionally referred to as Reiser3) stable and feature-complete and, with the exception of security updates and critical bug fixes, ceased development on it to concentrate on its successor, Reiser4» Criticism fsck «The tree rebuild process of ReiserFS's fsck has attracted much criticism by the *nix community: If the file system becomes so badly corrupted that its internal tree is unusable, performing a tree rebuild operation may further corrupt existing files or introduce new entries with unexpected contents,[19] but this action is not part of normal operation or a normal file system check and has to be explicitly initiated and confirmed by the administrator.» «ReiserFS v3 images should not be stored on a ReiserFS v3 partition (e.g., backups or disk images for emulators) without transforming them (e.g., by compressing or encrypting) in order to avoid confusing the rebuild. Reformatting an existing ReiserFS v3 partition can also leave behind data that could confuse the rebuild operation and make files from the old system reappear. This also allows malicious users to intentionally store files that will confuse the rebuilder. As the metadata is always in a consistent state after a file system check, corruption here means that contents of files are merged in unexpected ways with the contained file system's metadata. The ReiserFS successor, Reiser4, fixes this problem.»
This is even possible if you do not totally wipe (not just format, but totally overwrite) a previous ReiserFS v3 partition on the same disk - Reisers' fsck otherwise will try and 'restore' data from the previous partition, overwriting the current one.
Again, don't do that then.
So the claim amounts to: you can damage your data if you try to. I can do rm -rf /* as well, does that mean I should stop using GNU?
Can you see why some people see your approach as overbearing?
This is behaviour that's abhorrent and remains unfixed. There is no sane person with any understanding of filesystems who could possibly argue that ReiserFS v3 'needs no maintenance' ; even Reiser himself felt the problems were unresolvable, which is why Reiser v4 was started to fundamentally rewrite most of the filesystem to workaround that issue.
Do you really want to trust your data to a filesystem which has fundamental flaws which even the author abandoned rather than trying to fix?
Are there flaws that actually affect me? Why haven't I met them yet?
Me neither.
[snip]
And that doesn't mean we fully support ALL filesystems in the kernel; v3 is still built in the mainline kernel for backwards compatibility purposes - but no one should use it. YaST no longer supports installations with it. Upgrades will force migration to a different filesystem. This is good advice - Everyone should migrate to more sensible options than Reiserv3 as soon as possible. Anything is probably a more sensible option.
This is the piece that people are debating and where an answer from somebody knowledgeable would be useful. Is YaST going to suggest that you migrate a reiserfs filesystem to something else or is it going to refuse to continue the upgrade until you have done so? Is that all filesystems on the disks, or just those in the fstab?
And, does the upgrade block if data partitions are reiserfs, or only if the "/" is? -- Cheers / Saludos, Carlos E. R. (from 42.2 x86_64 "Malachite" at Telcontar)