On Tue, Dec 16, 2014 at 12:08:21PM +0100, Emmanuel Florac wrote: > Le Mon, 15 Dec 2014 13:25:00 +0100 > Emmanuel Florac <eflorac@xxxxxxxxxxxxxx> écrivait: > > > Reading the source I see that the error occured in xfs_buf_read_map, I > > suppose it's when xfsbufd tries to scan dirty metadata? This is a read > > error, so it could very well be a simple IO starvation at the > > controller level (as the controller probably gives priority to > > whatever writes are pending over reads). > > > > Maybe setting xfsbufd_centisecs to the max could help here? Trying > > right away... Any advice welcome. > > > > Alas, same thing; > > dmesg output: > > > ffff8800df1f5020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > ffff8800df1f5030: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > XFS (dm-0): Metadata corruption detected at xfs_inode_buf_verify+0x6c/0xb0, block 0xeffffff40 > XFS (dm-0): Unmount and run xfs_repair > XFS (dm-0): First 64 bytes of corrupted metadata buffer: > ffff8800df1f5000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > ffff8800df1f5010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > ffff8800df1f5020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > ffff8800df1f5030: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > XFS (dm-0): Metadata corruption detected at xfs_inode_buf_verify+0x6c/0xb0, block 0xeffffff40 > XFS (dm-0): Unmount and run xfs_repair So the underlying storage stack is returning zeros without any IO errors here. It's probably a lookup operation, so it simply fails and returns the error to userspace. Every one of these messages is a separate read IO, but they are all returning zeros. .... > XFS (dm-0): First 64 bytes of corrupted metadata buffer: > ffff8800df1f5000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > ffff8800df1f5010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > ffff8800df1f5020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > ffff8800df1f5030: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > XFS (dm-0): metadata I/O error: block 0xeffffff40 ("xfs_trans_read_buf_map") error 117 numblks 16 > XFS (dm-0): xfs_do_force_shutdown(0x1) called from line 383 of file fs/xfs/xfs_trans_buf.c. Return address = 0xffffffff8125cc90 > XFS (dm-0): I/O Error Detected. Shutting down filesystem > XFS (dm-0): Please umount the filesystem and rectify the problem(s) > XFS (dm-0): xfs_imap_to_bp: xfs_trans_read_buf() returned error 117. > XFS (dm-0): xfs_log_force: error 5 returned. > XFS (dm-0): xfs_log_force: error 5 returned. And here the same read error has occurred in a dirty transaction, and so the filesystem shut down. > There is no IO error at the RAID controller level, at all. The buffer > hasn't been overwritten with zeros, I'm pretty sure it actually timed > out and just read nothing. This is not a case for an IO error IMO, a > retry would almost certainly succeed; after all the problem occurred > after more than 8 hours of continuous heavy read/write activity. What you see above is a persistent corruption that has been reported several times as XFS has errored out and then re-read the data from disk multiple times. A retry would most certainly return zeros again. Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs