From: Paul F. <pg...@fo...> - 2004-08-31 03:47:19
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hi all -- is there a quick recipe for re-starting from a new pool? somehow my backuppc filesystem got corrupted -- so i'd like to, essentially, do the following: $ cd <the backuppc filesystem> $ mkdir /tmp/backuppc_saved_stuff $ cp -a <everything but the pool> /tmp/backuppc_saved_stuff $ cd / $ umount <the backuppc filesystem> $ mkfs <a new backuppc filesystem> $ mount <the new filesystem> $ cp -a /tmp/backuppc_saved_stuff <the new filesystem> $ /etc/init.d/backuppc start but i suspect there's a missing step in there -- how and when should the new pool directory be created? is an explicit step required? (secondary question: the previous filesystem for the pool was ext3. i'm running a 2.4.24 kernel. is ext3 the right choice? i'm not sure where my corruption came from -- i had corrupt directories, links from files to directories, other bad stuff. :-/ ) paul =--------------------- paul fox, pg...@fo... (arlington, ma, where it's 69.6 degrees) |
From: Daniel P. <da...@ri...> - 2004-08-31 05:01:30
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On 31 Aug 2004, Paul Fox wrote: > is there a quick recipe for re-starting from a new pool? somehow > my backuppc filesystem got corrupted -- so i'd like to, essentially, > do the following: My suggestion would be to copy the few configuration files to somewhere safe, remove the *whole* thing, install afresh, then copy the configuration files back. That would be easier and less error-prone than trying to prune out things that you don't want. [...] > (secondary question: the previous filesystem for the pool was ext3. > i'm running a 2.4.24 kernel. is ext3 the right choice? i'm not > sure where my corruption came from -- i had corrupt directories, links > from files to directories, other bad stuff. :-/ ) I would strongly recommend that you stick with ext3. The other three options are ext2, xfs and reiserfs, pretty much, which have their drawbacks compared to ext3. ext2, being non-journaled, rapidly becomes a three hour ordeal while waiting for a full fsck on an unclean reboot -- not my idea of fun with the huge size of many backuppc installs. xfs is metadata journaled only, so your actual data is not protected on a reboot. If the data itself has not been written on reboot, for security reasons it is nulled out where the metadata changed. While they have reduced the windows where this can regularly happen, it still does, and is the bane of my existence with some XFS-based systems I have to maintain. From experience, expect semi-regular data corruption if you have an unclean restart of your xfs using system. reiserfs is probably the best of the alternative filesystems, but suffers from two major issues: it still gets semi-regular reports of corruption problems and stability issues, and the developers have moved on to the new new thing, version 4. Personally, I don't use it and the main reason is that I don't trust the development style that was used. Treating the user-space verification and testing tools as the lowest, rather than highest, priority, struck me as the most obvious sign of a development process driven more by feature achievements than stability. Others, though, have had good things to say about it, so obviously YMMV. Also, I have not made recent use of it and, these days, the developers claim it to be stable and reliable. Daniel -- Consumption is a treatable disease. -- Tibor Kalman |
From: Paul F. <pg...@fo...> - 2004-08-31 13:46:43
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> > is there a quick recipe for re-starting from a new pool? somehow > > my backuppc filesystem got corrupted -- so i'd like to, essentially, > > do the following: > > My suggestion would be to copy the few configuration files to somewhere > safe, remove the *whole* thing, install afresh, then copy the > configuration files back. > > That would be easier and less error-prone than trying to prune out > things that you don't want. okay. that makes sense. as a followup to that -- should i be going to 2.1.0p1? i'm running 2.0.2 now. i was planning on upgrading at some point, when i was sure everyone else :-) thought the new code was stable. have we reached that point? > > (secondary question: the previous filesystem for the pool was ext3. ... > I would strongly recommend that you stick with ext3. The other three > options are ext2, xfs and reiserfs, pretty much, which have their > drawbacks compared to ext3. thanks for sharing your experiences. i'll stick with ext3. paul =--------------------- paul fox, pg...@fo... (arlington, ma, where it's 70.0 degrees) |
From: Daniel P. <da...@ri...> - 2004-09-05 02:01:36
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On 5 Sep 2004, Carl Wilhelm Soderstrom wrote: > On 09/01 12:31 , Daniel Pittman wrote: >> It is a passable all-round performance in terms of performance, but is >> *not* the fastest filesystem out there in 'ordered' data mode.[2] You >> will find that other filesystems, especially reiserfs, consistently >> outperform it at most tasks. >> >> Er, except file deletion, since everyone else seems to fall flat on >> that, while ext3 just keeps chugging along, for some reason. > > actually, by the benchmarks that I've seen, plus some practical experience > with reiserfs and ext3 on BackupPC data stores; reiserfs is pretty > comparable to ext3 in most regards. Reiserfs beats *everything* for creating > lots of small files; but it's still pretty comparable to ext3 > otherwise. *nod* That, I believe, is pretty much what I said. The note on deletion performance is drawn from two things: the issues with it that hit people pretty hard in the earlier days of reiserfs and were mostly optimized away, and the fact that there have been a few instances on this list of people having issues with it. :) > Since BackupPC deals with creating lots of little files on a regular basis; > reiserfs shows some definite gains here. I haven't seen much of an > improvement since I went to reiserfs on my backuppc directory; but I think > there *is* some there. (probably a lot more now, since my store is 10x the > size it was when I switched). Part of the reason I made sure to emphasize the drawbacks of all the filesystems is that there really isn't a *best* solution. I know what my preference is in terms of stability vs speed, and what I consider safe, but I can't say that is an absolute rule... Daniel -- I have a vision, and in that vision I'm standing on top of a building. God asks me 'Why do you love your Father?', and I say 'I do not know, Lord.' He offers me absolution and I thank him, and the shots ring out into the crowds below. -- D.J. Babb |