endless zpool scrub?

[Andriy Gapon]

I noticed that zpool scrub on a certain pool runs "like forever".
I decided to monitor its progress using periodic zpool status command, 
once in 10 seconds.
Here's a snippet from the capture around an interesting point.
Please notice two highlighted reports ('oops').
This is stable/7.
Thank you in advance for insights/comments.


   pool: tank
  state: ONLINE
  scrub: scrub in progress, 78.87% done, 0h31m to go
config:

         NAME        STATE     READ WRITE CKSUM
         tank        ONLINE       0     0     0
           ad6s2d    ONLINE       0     0     0

errors: No known data errors
   pool: tank
  state: ONLINE
  scrub: scrub in progress, 78.94% done, 0h31m to go
config:

         NAME        STATE     READ WRITE CKSUM
         tank        ONLINE       0     0     0
           ad6s2d    ONLINE       0     0     0

errors: No known data errors
   pool: tank
  state: ONLINE
  scrub: scrub in progress, 78.97% done, 0h31m to go
config:

         NAME        STATE     READ WRITE CKSUM
         tank        ONLINE       0     0     0
           ad6s2d    ONLINE       0     0     0

errors: No known data errors
   pool: tank
  state: ONLINE
  scrub: scrub in progress, 0.00% done, 233h25m to go
config:

         NAME        STATE     READ WRITE CKSUM
         tank        ONLINE       0     0     0
           ad6s2d    ONLINE       0     0     0
****oops, went back to 0%****

errors: No known data errors
   pool: tank
  state: ONLINE
  scrub: scrub in progress, 0.00% done, 259h47m to go
config:

         NAME        STATE     READ WRITE CKSUM
         tank        ONLINE       0     0     0
           ad6s2d    ONLINE       0     0     0

errors: No known data errors
   pool: tank
  state: ONLINE
  scrub: scrub in progress, 0.00% done, 186h50m to go
config:

         NAME        STATE     READ WRITE CKSUM
         tank        ONLINE       0     0     0
           ad6s2d    ONLINE       0     0     0

errors: No known data errors
   pool: tank
  state: ONLINE
  scrub: scrub in progress, 0.00% done, 186h45m to go
config:

         NAME        STATE     READ WRITE CKSUM
         tank        ONLINE       0     0     0
           ad6s2d    ONLINE       0     0     0

errors: No known data errors
   pool: tank
  state: ONLINE
  scrub: scrub in progress, 0.00% done, 306h30m to go
config:

         NAME        STATE     READ WRITE CKSUM
         tank        ONLINE       0     0     0
           ad6s2d    ONLINE       0     0     0

errors: No known data errors
   pool: tank
  state: ONLINE
  scrub: scrub in progress, 0.00% done, 292h19m to go
config:

         NAME        STATE     READ WRITE CKSUM
         tank        ONLINE       0     0     0
           ad6s2d    ONLINE       0     0     0

errors: No known data errors
   pool: tank
  state: ONLINE
  scrub: scrub in progress, 0.00% done, 231h16m to go
config:

         NAME        STATE     READ WRITE CKSUM
         tank        ONLINE       0     0     0
           ad6s2d    ONLINE       0     0     0

errors: No known data errors
   pool: tank
  state: ONLINE
  scrub: scrub in progress, 0.00% done, 283h55m to go
config:

         NAME        STATE     READ WRITE CKSUM
         tank        ONLINE       0     0     0
           ad6s2d    ONLINE       0     0     0

errors: No known data errors
   pool: tank
  state: ONLINE
  scrub: scrub in progress, 0.00% done, 232h8m to go
config:

         NAME        STATE     READ WRITE CKSUM
         tank        ONLINE       0     0     0
           ad6s2d    ONLINE       0     0     0

errors: No known data errors
   pool: tank
  state: ONLINE
  scrub: scrub in progress, 0.00% done, 164h37m to go
config:

         NAME        STATE     READ WRITE CKSUM
         tank        ONLINE       0     0     0
           ad6s2d    ONLINE       0     0     0

errors: No known data errors
   pool: tank
  state: ONLINE
  scrub: scrub in progress, 0.00% done, 183h40m to go
config:

         NAME        STATE     READ WRITE CKSUM
         tank        ONLINE       0     0     0
           ad6s2d    ONLINE       0     0     0

errors: No known data errors
   pool: tank
  state: ONLINE
  scrub: scrub in progress, 0.00% done, 166h21m to go
config:

         NAME        STATE     READ WRITE CKSUM
         tank        ONLINE       0     0     0
           ad6s2d    ONLINE       0     0     0

errors: No known data errors
   pool: tank
  state: ONLINE
  scrub: scrub stopped with 0 errors on Wed Nov 26 12:02:02 2008
config:

         NAME        STATE     READ WRITE CKSUM
         tank        ONLINE       0     0     0
           ad6s2d    ONLINE       0     0     0
****oops, scrub is reported as stopped****

errors: No known data errors
   pool: tank
  state: ONLINE
  scrub: scrub in progress, 0.00% done, 127h29m to go
config:

         NAME        STATE     READ WRITE CKSUM
         tank        ONLINE       0     0     0
           ad6s2d    ONLINE       0     0     0

errors: No known data errors

-- 
Andriy Gapon