Hi All, I encounter the following output from time to time. Since xfs is built on our own virtual disk, it's more likely that our vdisk is buggy. Can anyone tell me how to figure out the on-disk location given the block number? Does it follow the following formula? On-disk location = <block number from metadata I/O error> * <bsize of data section of xfs_info> However, the result from the above formula suggests the metadata is out of range of my disk, confused... Another question is the corrupted metadata buffer always start with 8 bytes of '8' character. Does xfs use '8' as any magic label? I'm using centos-7.2, kernel 3.10.0-327.el7. XFS (md_d27): Metadata corruption detected at xfs_agf_read_verify+0x70/0x120 [xfs], block 0x1e8ffa08 XFS (md_d27): Unmount and run xfs_repair XFS (md_d27): First 64 bytes of corrupted metadata buffer: ffff88042fc69000: 38 38 38 38 38 38 38 38 00 00 00 00 00 00 00 00 88888888........ ffff88042fc69010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ ffff88042fc69020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ ffff88042fc69030: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ XFS (md_d27): metadata I/O error: block 0x1e8ffa08 ("xfs_trans_read_buf_map") error 117 numblks 8 XFS (md_d27): page discard on page ffffea000b34f900, inode 0x23e, offset 362840064. XFS (md_d27): Metadata corruption detected at xfs_agf_read_verify+0x70/0x120 [xfs], block 0x1e8ffa08 XFS (md_d27): Unmount and run xfs_repair # xfs_info /mnt/md/27 meta-data=/dev/md_d27 isize=256 agcount=32, agsize=10682336 blks = sectsz=4096 attr=2, projid32bit=1 = crc=0 finobt=0 data = bsize=4096 blocks=341834752, imaxpct=5 = sunit=32 swidth=64 blks naming =version 2 bsize=4096 ascii-ci=0 ftype=0 log =internal bsize=4096 blocks=166911, version=2 = sectsz=4096 sunit=1 blks, lazy-count=1 realtime =none extsz=4096 blocks=0, rtextents=0 #cat /proc/partition 253 1728 1367342592 md_d27 -Vaughan -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html