Errors on tape drives
 

Hi,

We are getting a lot of errors on tape drives attached to our Suse linux host

OS is running
SUSE Linux Enterprise Server 11 (x86_64)
VERSION = 11
PATCHLEVEL = 1

and we have Netbackup software running for backups

But we see a lot of errors in the OS logs and Netbackup application team wants us to investigate these .Please see below

Jul 31 05:50:39 PNIOYNBMDS01 kernel: [994667.393761] st3: Sense Key : Medium Error [current]
Jul 31 05:50:39 PNIOYNBMDS01 kernel: [994667.393770] Info fld=0x10000
Jul 31 05:50:39 PNIOYNBMDS01 kernel: [994667.393772] st3: Add. Sense: Unrecovered read error


Jul 31 06:17:21 PNIOYNBMDS01 kernel: [996268.793836] st3: Error d0000 (driver bt 0x0, host bt 0xd).
Jul 31 06:17:21 PNIOYNBMDS01 kernel: [996268.793840] st3: Error on write filemark.


Jul 31 08:24:34 PNIOYNBMDS01 kernel: [1003901.710823] st5: Error d0000 (driver bt 0x0, host bt 0xd).
Jul 31 08:24:34 PNIOYNBMDS01 kernel: [1003901.710826] st5: Error on write filemark.


mt command returns I/O erros which should not be the case in a ideal scenario.

nibackup@PNIOYNBMDS01:~> sudo mt -f /dev/nst5 status
mt: /dev/nst5: rmtopen failed: Device or resource busy
nibackup@PNIOYNBMDS01:~> sudo mt -f /dev/nst6 status
mt: /dev/nst6: rmtopen failed: Input/output error
nibackup@PNIOYNBMDS01:~> sudo mt -f /dev/nst3 status
mt: /dev/nst3: rmtopen failed: Input/output error
nibackup@PNIOYNBMDS01:~> sudo mt -f /dev/nst0 status
mt: /dev/nst0: rmtopen failed: Device or resource busy

tar -rvf /dev/nst9 /usr/openv/netbackup/logs/bptm/log.072412
tar: /dev/nst9: Cannot read: Input/output error
tar: At beginning of tape, quitting now
tar: Error is not recoverable: exiting now


sudo dmesg |grep -i st0
[315578.970760] st0: Sense Key : Medium Error [current]
[315578.970769] st0: Add. Sense: Unrecovered read error
[316485.505277] st0: Error d0000 (driver bt 0x0, host bt 0xd).
[317469.757748] st0: Error d0000 (driver bt 0x0, host bt 0xd).
[318370.811881] st0: Error d0000 (driver bt 0x0, host bt 0xd).
[318370.811885] st0: Error on write filemark.
[422201.848816] st 3:0:1:0: Attached scsi tape st0
[422201.848819] st 3:0:1:0: st0: try direct i/o: yes (alignment 4 B)
[423211.144150] st0: Block limits 1 - 16777215 bytes.


Please if you can suggest on them .backup team has changeda lot of tapes and they also regularly clean their tape drives but the error does not stop and the error is coming on all tape drives configured and we have around 12 tape drives attached to the server

Please if somebody can help on this as we are not able to find much info on this .

Thanks,
Abhishek

Hi,

Sounds like

1. Your tape-drive is not working 100% and requires cleaning or to be replaced. Heads, motor and belt can get unreliable.
2. Your tapes have been used to many times and are not reliable anymore. I swap them every 40 times used.
3. You have a not correct working tape driver. This can be due to an update
4. Your power-supply is unreliable. This can be due to age or dust

Most likely are the first two options. I hope this helps you to narrow down the possible problems.

Regards,
Henri B.