On 5/23/12 2:33 PM, Andreas Dilger wrote: > On 2012-05-23, at 12:48 PM, Eric Sandeen wrote: >> I'll try to look into this but just wanted to put it out there. >> >> After creating a 32T fs and filling it with 1T preallocated files, >> I get quite a lot of corruption; this wasn't really the test >> I wanted to do, I wanted to then remove a file with mostly >> high blocks, run fsstress, and test recovery :( > > Hmm, we've done full-filesystem write + read +verify + e2fsck up to > 128TB (took several days to write and read so much data) with RHEL6 > without similar problems (up to 32TB on RHEL5) using real disks. > > We don't use fallocate() or loop devices, so it may be that some > problems are therein, or possibly with newer kernels. > > Presumably this is using XFS for the backing loop file? I don't > anticipate problems with that, but there may be strange interactions > between fallocate(), sparse files, and TRIM/DISCARD? It is backed by XFS, yes. I don't think I'm freeing any blocks during the test, so I wouldn't expect discard to come into it. Really, all it should be doing is writing fairly small amounts of metadata, right? I'll keep investigating. -Eric >> # uname -r >> 3.4.0-rc4+ >> # truncate --size 32t imagefile2 >> # mkfs.ext4 -F imagefile2 >> mke2fs 1.42.3 (14-May-2012) >> ... >> # mount -o loop imagefile2 /mnt/scratch >> # for I in `seq 1 32`; do fallocate -l 1t /mnt/scratch/1tfile$I; done >> # umount /mnt/scratch > > Did you try sync here, or running e2fsck on the loop device instead > of the backing file? It looks like nothing was written to disk... > >> # time e2fsck -fn imagefile2 >> e2fsck 1.42.3 (14-May-2012) >> <many many many lines snipped> >> Free blocks count wrong for group #131072 (0, counted=32768). >> Fix? no >> >> Free blocks count wrong for group #131073 (0, counted=32768). >> Fix? no >> >> Free blocks count wrong for group #131074 (0, counted=4164). >> Fix? no >> >> Free blocks count wrong (3, counted=4294967299). >> Fix? no >> >> >> imagefile2: ********** WARNING: Filesystem still has errors ********** >> >> imagefile2: 43/536870912 files (0.0% non-contiguous), 8589934589/8589934592 blocks >> >> real 27m40.133s >> user 27m12.886s >> sys 0m6.238s >> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-ext4" in >> the body of a message to majordomo@xxxxxxxxxxxxxxx >> More majordomo info at http://vger.kernel.org/majordomo-info.html > > > Cheers, Andreas > > > > > -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
