Checksum errors on single drive

[sanosuke001]

Over the last couple months a drive I recently replaced is having checksum errors. This past scrub it was at 13 (below is chart). Right now, I have a SAS cable connecting four drives a piece (8 total, two SAS cables) to a SAS controller card (not RAID as I am having FreeNAS do it's ZFS thing). Now, if it is the drive (I don't see checksum errors on other devices, just da7) do I need to worry about just checksum errors or do they happen sometimes? (though, not sure why just that drive) If not, could it be the cable even though it's one cable for four drives? (granted, internally it's many cables).

Thanks for the input.

Code:

  pool: raid
 state: ONLINE
status: One or more devices has experienced an unrecoverable error.  An
        attempt was made to correct the error.  Applications are unaffected.
action: Determine if the device needs to be replaced, and clear the errors
        using 'zpool clear' or replace the device with 'zpool replace'.
   see: http://www.sun.com/msg/ZFS-8000-9P
  scan: scrub repaired 237K in 18h52m with 0 errors on Thu Feb 14 18:52:15 2013
config:

        NAME                                            STATE     READ WRITE CKSUM
        raid                                            ONLINE       0     0     0
          raidz1-0                                      ONLINE       0     0     0
            gptid/228f385c-57a2-11e1-880e-406186cc6422  ONLINE       0     0     0
            gptid/236662fc-57a2-11e1-880e-406186cc6422  ONLINE       0     0     0
            gptid/244133d4-57a2-11e1-880e-406186cc6422  ONLINE       0     0     0
            gptid/250d4db1-57a2-11e1-880e-406186cc6422  ONLINE       0     0     0
            gptid/25d98a18-57a2-11e1-880e-406186cc6422  ONLINE       0     0     0
            gptid/26a72276-57a2-11e1-880e-406186cc6422  ONLINE       0     0     0
            gptid/dda8c3f7-ac2c-11e1-90b8-406186cc6422  ONLINE       0     0     0
            gptid/28403c8f-57a2-11e1-880e-406186cc6422  ONLINE       0     0    13

errors: No known data errors

 

[paleoN]

Now, if it is the drive (I don't see checksum errors on other devices, just da7) do I need to worry about just checksum errors or do they happen sometimes?

Yes and sometimes yes.

If not, could it be the cable even though it's one cable for four drives? (granted, internally it's many cables).

Also, yes.

Code:

glabel status

smartctl -q noserial -a /dev/da7

Continuing repeated checksum errors are a sign of a problem.

 

[sanosuke001]

Thanks for the feedback; I'll run some tests this weekend.

 

[cyberjock]

Normally cable problems manifest themselves as tons of Ultra-DMA CRC errors. This is typically SMART parameter 199 if you want to check out the SMART data on your hard drives.

In Windows XP and newer, if you get 5 of them between bootups then the Ultra-DMA is disabled on the hard drive. You will typically figure out VERY quickly that something is wrong with your machine. It will start performing extremely poorly.