On 3/6/08, Daniel Pittman <[EMAIL PROTECTED]> wrote: > > Michael Hipp <[EMAIL PROTECTED]> writes: > > > Oliver Brakmann wrote: > >> On Wed, 2008-03-05 17:04, David Kempe wrote... > > > >>> Importantly, you can have data-loss on XFS if you lose power suddenly, > >>> perhaps more so than ext3. When files get corrupted on XFS, I have > >>> noticed they go to zero size > >> > >> I believe I read somewhere that that has been fixed some time ago. > > > > Oliver, could you perchance find a reference for that? Dapper really > > isn't that old. > > > The change was in 2.6.24, so will be in Hardy, but is not present in any > file system before that. > > There were some data corruption bugs around 2.6.17, none of which were > ever in an Ubuntu release that I am aware of, and which have since been > fixed; these are unlikely to be what the posters here are describing.[1] > > > > Not disagreeing. I'd *like* to use XFS, I just feel burned by it. An > > indicator that this issue has been solidly addressed would be great > > news. > > > It should be more or less as solid as writeback ext3 now, but less safe > than data journaled ext3. > > > > Some things to read: > > http://www.debian-administration.org/articles/388#comment_40 > > (read all comments to the end) > > > This comment, and the few subsequent, are a misunderstanding of how > things work. The problem illustrated is not that "enterprise > applications do their own data recovery." > > The problem is that POSIX file semantics make some things safe and some > things dangerous regarding your files. The applications that see NULL > content would probably be corrupt on disk, since they have changed their > size and (potentially) appended random data to the end of their content. > > The sad part is that most application developers don't really understand > POSIX I/O semantics and, so, many popular applications are vulnerable to > this. > > (hint for those at home: write your content to a new file and rename it > over the existing one; this is atomic, assuring you that the new or the > old file is there, nothing in between. > > for bonus points include some recovery to determine if the new version > is complete and coherent, then offer to complete the task.) > > > > http://www.tummy.com/journals/entries/jafo_20041226_015752 > > > For a user who claims to care about data integrity this poster seems to > have little actual clue: JFS is an exciting choice, at best, and > reiserfs... > > Well, hey, the point someone starts talking about using reiserfs and > data integrity being important to them you can more or less know they > don't really understand how data integrity is achieved. > > reiserfs (3) has significant issues, many of which are performance or > data integrity related, and is close to impossible to recover if > /anything/ goes wrong.[2] > > Regards, > Daniel > > Footnotes: > [1] Their symptoms were completely different, much nastier, and fairly > identifiable. Zero length or null-filled files were not among them. > > [2] ...or you happen to store anything that looks like a reiserfs > filesystem inside them when you run the fsck tools.[3] > > [3] This is highly amusing to me as I recall the excitement when the > developers announced a library version of reiserfs intended as a > "compound document" format for applications to use, delivering the > same performance as the file system they were stored in... > > > > > > -- > ubuntu-server mailing list > [email protected] > https://lists.ubuntu.com/mailman/listinfo/ubuntu-server > More info: https://wiki.ubuntu.com/ServerTeam >
Hey, Thought I'd share my experiences with reiserfs... I'm using reiserfs on my mythtv box with a 4x400GB software raid5 array (~1.2TB usable) and it has been ok, but also unstressed so I won't go as far as vouching for it in a production environment. It's strength seems to lie in large numbers of small files rather than the large audio/video you're using. On the recovery side though, I was fiddling with the underlying lvm & md and managed to bork the system. I rebuilt the whole thing with the exact same parameters as I used originally and ran the reiserfs recovery tool to find it pulling files out of my (reiserfs formatted) VM images as well as the files actually in the fs. I ended up getting back _most_ of my data and had backups of the vms, so it wasn't a complete loss. I think the tried and tested 'just works' of ext3 would probably be a better choice in a potential recovery situation. My new place has brown outs during almost every storm and I've yet to invest in a UPS, the system has so far come back up without issue. cheers, Owen. -- If it aint broke, fix it 'till it is. --
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