I have an interesting problem on my home file/media server that I can't track down(debian 8.11). I am constantly seeing the following message in dmesg for the last few days:
Buffer I/O error on device sdg, logical block 5
Sometime I'll get a bit more in the logs
[331645.357795] Buffer I/O error on device sdg, logical block 7 [331826.255867] sd 14:0:0:0: [sdg] Command timed out [331826.255875] sd 14:0:0:0: [sdg] [331826.255879] Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE [331826.255883] sd 14:0:0:0: [sdg] [331826.255886] Sense Key : Not Ready [current] [331826.255892] sd 14:0:0:0: [sdg] [331826.255896] Add. Sense: Logical unit is in process of becoming ready [331826.255899] sd 14:0:0:0: [sdg] CDB: [331826.255902] Read(10): 28 00 00 00 00 00 00 00 01 00 [331826.255915] end_request: I/O error, dev sdg, sector 0 [331826.257606] Buffer I/O error on device sdg, logical block 0 [331833.213945] sd 14:0:0:0: timing out command, waited 180s [331833.215687] sd 14:0:0:0: [sdg] Command timed out [331833.215692] sd 14:0:0:0: [sdg] [331833.215695] Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE [331833.215699] sd 14:0:0:0: [sdg] [331833.215701] Sense Key : Not Ready [current] [331833.215717] sd 14:0:0:0: [sdg] [331833.215731] Add. Sense: Logical unit is in process of becoming ready [331833.215735] sd 14:0:0:0: [sdg] CDB: [331833.215737] Read(10): 28 00 00 00 00 01 00 00 07 00
The problem is, I can't find a figure out what device sdg is?!?!
I am assuming it's block device of some sort, however there are only 6 physical drives in my server(sda, sdb, sdc, sdd, sde, sdf)
- sda = OS installation drive. Physical disk.
- sdb & sdc - MDADM RAID 0 as /dev/md1. Physical disks.
- sdd & sde - MDADM RAID 0 as /dev/md0. Physical disks.
- sdf - External USB drive used for nightly backups.
I've tried running
fdisk -l /dev/sdg and the command just hangs.
ls -all /dev/disk/by-id/ | grep sdg returns 0 results.
I plugged in a USB thumb drive and it mounted as /dev/sdh, so it skipped /dev/sdg for some reason.
smartctl -a /dev/sdg returns the following:
smartctl 6.4 2014-10-07 r4002 [x86_64-linux-3.16.0-4-amd64] (local build) Copyright (C) 2002-14, Bruce Allen, Christian Franke, www.smartmontools.org Read Device Identity failed: scsi error device will be ready soon A mandatory SMART command failed: exiting. To continue, add one or more '-T permissive' options.
cat /proc/diskstats returns:
8 96 sdg 596 867 1458 163968604 0 0 0 0 1 68509944 164194776
There is nothing in /etc/fstab referencing /dev/sdg.
Other than running samba/ssh for sharing files on my home network, the only other application installed is Plex media server, however I wouldn't think any of those applications would be creating block devices on my system.
It's a bit of a relief to know that it's not any of my disks holding my data that are throwing errors, but now the question is how do I figure out what sdg is and why is it throwing these errors?
Any ideas on how I track this sdg drive down?