I have an 8TiB disk attached via UBS3 and formatted into 3 EXT3 partitions which I use as a backup drive (it's plugged into a SATA cradle).
The disk has been attached and mounted for several days without being explicitly written to (I backed up some data a couple of days ago).
I happened to take a look at dmesg and spotted the following (this is filtered to show only entries matching the disk name, sdg):
[393945.628890] EXT4-fs (sdg2): error count since last fsck: 4
[393945.628894] EXT4-fs (sdg2): initial error at time 1589268773: ext4_validate_block_bitmap:406
[393945.628897] EXT4-fs (sdg2): last error at time 1589336019: ext4_validate_block_bitmap:406
[394076.698059] EXT4-fs (sdg1): error count since last fsck: 103
[394076.698063] EXT4-fs (sdg1): initial error at time 1589216157: ext4_validate_block_bitmap:406
[394076.698066] EXT4-fs (sdg1): last error at time 1589372294: ext4_lookup:1590: inode 186081476
I've not run fsck on this disk since it was partitioned and formatted. Given that fsck has not been run what is finding the errors and how concerned should I be?
When I rebooted the system this morning I checked dmesg again and found (again filtered to show only entries matching sdg)
[ 261.721822] sd 9:0:0:0: [sdg] Spinning up disk...
[ 274.051062] sd 9:0:0:0: [sdg] 15628053168 512-byte logical blocks: (8.00 TB/7.28 TiB)
[ 274.051065] sd 9:0:0:0: [sdg] 4096-byte physical blocks
[ 274.051137] sd 9:0:0:0: [sdg] Write Protect is off
[ 274.051140] sd 9:0:0:0: [sdg] Mode Sense: 43 00 00 00
[ 274.051297] sd 9:0:0:0: [sdg] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
[ 274.051498] sd 9:0:0:0: [sdg] Optimal transfer size 33553920 bytes not a multiple of physical block size (4096 bytes)
[ 274.134309] sdg: sdg1 sdg2 sdg3
[ 274.135296] sd 9:0:0:0: [sdg] Attached SCSI disk
[ 274.654835] EXT4-fs (sdg3): mounting ext3 file system using the ext4 subsystem
[ 274.696860] EXT4-fs (sdg3): warning: mounting fs with errors, running e2fsck is recommended
[ 274.766709] EXT4-fs (sdg1): mounting ext3 file system using the ext4 subsystem
[ 274.795109] EXT4-fs (sdg1): warning: mounting fs with errors, running e2fsck is recommended
[ 274.825210] EXT4-fs (sdg2): mounting ext3 file system using the ext4 subsystem
[ 274.891191] EXT4-fs (sdg2): warning: mounting fs with errors, running e2fsck is recommended
[ 275.713323] EXT4-fs (sdg2): mounted filesystem with ordered data mode. Opts: (null)
[ 276.460528] EXT4-fs (sdg3): mounted filesystem with ordered data mode. Opts: (null)
[ 276.499085] EXT4-fs (sdg1): mounted filesystem with ordered data mode. Opts: (null)
[ 578.549827] EXT4-fs (sdg1): error count since last fsck: 103
[ 578.549830] EXT4-fs (sdg1): initial error at time 1589216157: ext4_validate_block_bitmap:406
[ 578.549832] EXT4-fs (sdg1): last error at time 1589372294: ext4_lookup:1590: inode 186081476
[ 578.549836] EXT4-fs (sdg3): error count since last fsck: 47
[ 578.549837] EXT4-fs (sdg3): initial error at time 1589268525: htree_dirblock_to_tree:1022: inode 31604737: block 126419458
[ 578.549840] EXT4-fs (sdg3): last error at time 1589380312: ext4_lookup:1594: inode 33701921
[ 578.549844] EXT4-fs (sdg2): error count since last fsck: 4
[ 578.549845] EXT4-fs (sdg2): initial error at time 1589268773: ext4_validate_block_bitmap:406
[ 578.549847] EXT4-fs (sdg2): last error at time 1589336019: ext4_validate_block_bitmap:406
[ 639.938843] EXT4-fs (sdg1): mounting ext3 file system using the ext4 subsystem
[ 640.950738] EXT4-fs (sdg1): mounted filesystem with ordered data mode. Opts: (null)
[ 650.900006] EXT4-fs (sdg2): mounting ext3 file system using the ext4 subsystem
[ 651.207658] EXT4-fs (sdg2): mounted filesystem with ordered data mode. Opts: (null)
[ 658.836040] EXT4-fs (sdg3): mounting ext3 file system using the ext4 subsystem
[ 659.084558] EXT4-fs (sdg3): mounted filesystem with ordered data mode. Opts: (null)
So the system knows there are errors and has still mounted the disk without displaying any warnings other than the entries in dmesg.
Roughly 30 minutes later I checked again because I was curious now and found:
[ 955.353027] EXT4-fs (sdg2): error count since last fsck: 3248
[ 955.353031] EXT4-fs (sdg2): initial error at time 1589268773: ext4_validate_block_bitmap:406
[ 955.353033] EXT4-fs (sdg2): last error at time 1589437923: ext4_map_blocks:604: inode 103686210: block 1947002998
[ 955.353039] EXT4-fs (sdg1): error count since last fsck: 103
[ 955.353040] EXT4-fs (sdg1): initial error at time 1589216157: ext4_validate_block_bitmap:406
[ 955.353042] EXT4-fs (sdg1): last error at time 1589372294: ext4_lookup:1590: inode 186081476
[ 956.751484] EXT4-fs error (device sdg2): ext4_map_blocks:604: inode #103686210: block 1947002998: comm updatedb.mlocat: lblock 12 mapped to illegal pblock 1947002998 (length 1)
[ 956.767496] EXT4-fs error (device sdg2): ext4_map_blocks:604: inode #103686210: block 1947002998: comm updatedb.mlocat: lblock 12 mapped to illegal pblock 1947002998 (length 1)
[ 956.782683] EXT4-fs warning (device sdg2): htree_dirblock_to_tree:994: inode #103686210: lblock 12: comm updatedb.mlocat: error -117 reading directory block
Eeek! The error count has increased for sdg2!
Again I've not explicitly written to the disk all this time.
Before partitioning & formatting the drive with gparted I used fsck to run a bad block scan (took several days) and no errors were found. This is also a new disk. For this reason, I'm reasonably confident that the hardware is good.
What is possibly going on here? How worried should I be about the integrity of filesystems on this disk? What should my next steps be?
