[OmniOS-discuss] zdb doesn't find a pool

[Richard Elling]

> On Apr 15, 2017, at 7:31 PM, Dan McDonald <danmcd at omniti.com> wrote:
> 
> That woz was the result of zpool split is news to me (or I missed it, in which case I apologize).
> 
> I wonder if a toy test with files ala the zfs test suite can reproduce this?
> 
> - create 3-way mirror
> - zdb
> - split one disk
> - zdb original and split-created pool

hint: when provided a pool name, zdb looks in /etc/zfs/zpool.cache to determine the
poolname to devices mapping. Using the -e (exported) option causes zdb to read 
ZFS labels on the disks to locate the devices mapping. Since zdb runs in userland and
can be run by non-root users, it has no knowledge of internal kernel state. "zdb -C"
will pretty-print the packed nvlist cachefile for your viewing pleasure
 -- richard

> 
> Adding illumos zfs list.
> 
> Dan
> 
> Sent from my iPhone (typos, autocorrect, and all)
> 
>> On Apr 15, 2017, at 9:19 PM, Michael Mounteney <gate03 at landcroft.co.uk> wrote:
>> 
>> Hello and apology to Dan to whom I've already mentioned this matter on
>> IRC.
>> 
>> Summary:  zdb doesn't see a pool specified by name.
>> 
>> My (home) server has three pools so:
>> 
>> ================================================
>> # zpool status
>> pool: rpool
>> state: ONLINE
>> scan: scrub repaired 0 in 0h2m with 0 errors on Sun Feb 19 14:01:41
>> 2017 config:
>> 
>>       NAME        STATE     READ WRITE CKSUM
>>       rpool       ONLINE       0     0     0
>>         c2t0d0s0  ONLINE       0     0     0
>> 
>> errors: No known data errors
>> 
>> pool: vault
>> state: ONLINE
>> scan: none requested
>> config:
>> 
>>       NAME          STATE     READ WRITE CKSUM
>>       vault         ONLINE       0     0     0
>>         raidz2-0    ONLINE       0     0     0
>>           c2t1d0s0  ONLINE       0     0     0
>>           c2t2d0s0  ONLINE       0     0     0
>>           c2t3d0s0  ONLINE       0     0     0
>>           c2t5d0s0  ONLINE       0     0     0
>> 
>> errors: No known data errors
>> 
>> pool: woz
>> state: ONLINE
>> scan: resilvered 359G in 8h21m with 0 errors on Fri Mar 17 03:16:51
>> 2017 config:
>> 
>>       NAME        STATE     READ WRITE CKSUM
>>       woz         ONLINE       0     0     0
>>         c2t4d0s0  ONLINE       0     0     0
>> 
>> errors: No known data errors
>> ================================================
>> 
>> However, zdb won't see the pool 'woz':
>> 
>> ================================================
>> # zdb vault | head -4
>> 
>> Cached configuration:
>>       version: 5000
>>       name: 'vault'
>> # zdb woz
>> zdb: can't open 'woz': No such file or directory
>> # zdb -l /dev/rdsk/c2t4d0s0 | head -6
>> --------------------------------------------
>> LABEL 0
>> --------------------------------------------
>>   version: 5000
>>   name: 'woz'
>>   state: 0
>> ================================================
>> 
>> So zdb finds pool 'vault' alright but not 'woz'.  It will however see
>> 'woz' if it's referred-to by disk.  The difference which I think might
>> be crucial is that 'vault' was created via zpool create, whereas 'woz'
>> was created via zpool split.  In the full output of zdb
>> -l /dev/rdsk/c2t4d0s0 (omitted here for brevity), there are four labels
>> numbered 0 to 3.  The output is much shorter as well;  it doesn't list
>> the individual file objects as zdb vault does.
>> 
>> Is this worth a mention on https://www.illumos.org/issues ?
>> 
>> ______________
>> Michael Mounteney
>> _______________________________________________
>> OmniOS-discuss mailing list
>> OmniOS-discuss at lists.omniti.com
>> http://lists.omniti.com/mailman/listinfo/omnios-discuss
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