I have a 4 device volume with raid5 - trying to remove one of the devices (plenty of free space) and I get an almost immediate segfault. Scrub shows no errors, repair show space cache invalid but nothing else (I remounted with clear cache to be safe). Lots of corrupt on bdev (for 3 out of 4 drives), but I have no file access issues that I know of. Thanks! Output below: http://pastebin.com/AnrmZrt2 - Craig -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Craig Johnson posted on Fri, 16 Aug 2013 11:50:59 -0500 as excerpted:> I have a 4 device volume with raid5 - trying to remove one of the > devices (plenty of free space) and I get an almost immediate segfault. > Scrub shows no errors, repair show space cache invalid but nothing > else (I remounted with clear cache to be safe). Lots of corrupt on bdev > (for 3 out of 4 drives), but I have no file access issues that I know > of. Thanks!Last I knew (kernel 3.10, where it was introduced, but I haven''t seen any suggestion that 3.11 fixes all the problems yet), btrfs raid5/6 wasn''t yet ready for anything like real use yet -- the all-OK code was there, but it couldn''t yet cope with devices disappearing -- recreating the missing content from the checksums didn''t yet work. So "an almost immediate segfault" might be expected if you actually remove a device from a btrfs raid5/6, because only the all-OK code is actually there, it''s writing the checksums but it isn''t prepared to actually use them yet. Btrfs raid0/1/10 should be usable, and /reasonably/ stable (for a filesystem still under development with bugs actively being fixed with each kernel release, that is), however (tho raid1 actually means two-way- mirror, no matter the number of devices). FWIW, I''m using btrfs raid1 here, but I have backups both to a second btrfs raid1 and to reiserfs (my previous filesystem and what I still use on "spinning rust, but it''s not suitable for ssds, so I use btrfs on them), because btrfs IS still experimental. -- Duncan - List replies preferred. No HTML msgs. "Every nonfree program has a lord, a master -- and if you use the program, he is your master." Richard Stallman -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Quoting Craig Johnson (2013-08-16 12:50:59)> I have a 4 device volume with raid5 - trying to remove one of the > devices (plenty of free space) and I get an almost immediate segfault. > Scrub shows no errors, repair show space cache invalid but nothing > else (I remounted with clear cache to be safe). Lots of corrupt on > bdev (for 3 out of 4 drives), but I have no file access issues that I > know of. Thanks! > > Output below: > > http://pastebin.com/AnrmZrt2Hi Craig, Just double checking how you setup the device removal? This is a 3.11 arch kernel? Which rc was it based from? -chris -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
I did this on 3.11-rc5 kernel I compiled a few days ago. 3.11.0-1-ARCH-00013-g584d88b-dirty. Thanks! On Sat, Aug 17, 2013 at 7:05 AM, Chris Mason <chris.mason@fusionio.com> wrote:> Quoting Craig Johnson (2013-08-16 12:50:59) >> I have a 4 device volume with raid5 - trying to remove one of the >> devices (plenty of free space) and I get an almost immediate segfault. >> Scrub shows no errors, repair show space cache invalid but nothing >> else (I remounted with clear cache to be safe). Lots of corrupt on >> bdev (for 3 out of 4 drives), but I have no file access issues that I >> know of. Thanks! >> >> Output below: >> >> http://pastebin.com/AnrmZrt2 > > Hi Craig, > > Just double checking how you setup the device removal? This is a 3.11 > arch kernel? Which rc was it based from? > > -chris >-- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html