On Monday 28 May 2007 14:53:55 Pallai Roland wrote: > On Friday 25 May 2007 02:05:47 David Chinner wrote: > > "-o ro,norecovery" will allow you to mount the filesystem and get any > > uncorrupted data off it. > > > > You still may get shutdowns if you trip across corrupted metadata in > > the filesystem, though. > > This filesystem is completely dead. > [...] I tried to make a md patch to stop writes if a raid5 array got 2+ failed drives, but I found it's already done, oops. :) handle_stripe5() ignores writes in this case quietly, I tried and works. So how I lost my file system? My first guess about partially successed writes wasn't right: there wasn't real write to the disks after the second disk has been kicked, so the scenario is same to a simple power loss from this point of view. Am I thinking right? There's an another layer I used on this box between md and xfs: loop-aes. I used it since years and rock stable, but now it's my first suspect, cause I found a bug in it today: I assembled my array from n-1 disks, and I failed a second disk for a test and I found /dev/loop1 still provides *random* data where /dev/md1 serves nothing, it's definitely a loop-aes bug: /dev/loop1: [0700]:180907 (/dev/md1) encryption=AES128 multi-key-v3 hq:~# dd if=/dev/md1 bs=1k count=128 skip=128 >/dev/null dd: reading `/dev/md1': Input/output error 0+0 records in 0+0 records out hq:~# dd if=/dev/loop1 bs=1k count=128 skip=128 | md5sum 128+0 records in 128+0 records out 131072 bytes (131 kB) copied, 0.027775 seconds, 4.7 MB/s e2548a924a0e835bb45fb50058acba98 - (!!!) hq:~# dd if=/dev/loop1 bs=1k count=128 skip=128 | md5sum 128+0 records in 128+0 records out 131072 bytes (131 kB) copied, 0.030311 seconds, 4.3 MB/s c6a23412fb75eb5a7eb1d6a7813eb86b - (!!!) It's not an explanation to my screwed up file system, but for me it's enough to drop loop-aes. Eh. -- d - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
