zfs discuss - Jul 2009 - Problem with mounting ZFS from USB drive

I''m a new user of ZFS and I have an external USB drive which contains
a ZFS pool with file system. It seems that it does not get auto mounted
when I plug in the drive. I''m running osol-0811.

How can I manually mount this drive? It has a pool named rpool on it.
Is there any diagnostics commands that can be used to investigate the
contents of the pool or repair a damaged file system ?

rmformat shows that the physical name of the USB device is: /dev/rdsk/c4t0d0p0
If I try ''# zpool import" I get:
  pool: rpool
    id: 3765122753259138111
 state: UNAVAIL
status: The pool was last accessed by another system.
action: The pool cannot be imported due to damaged devices or data.
   see: http://www.sun.com/msg/ZFS-8000-EY
config:
        rpool       UNAVAIL  newer version
          c4t0d0s0  ONLINE

I suppose this means that the data is corrupted in some way
although I never observed any write errors when it was created.
This drive was formatted with zfs by the osol-0906 installer.

Another question is about backward compatibility of ZFS. If I create
a ZFS system under say osol-0906 can I access this system on older
nv builds and Solaris 10 ?

Thanks
/Karl D
-- 
This message posted from opensolaris.org

I''m no expert but I think you need to export a zfs volume before you
remove it or it''ll complain when you try to import it on another
system.

"zfs admin guide pg. 89"

zfs export poolName

You can do a zfs -f import to import it anyway.

Hua-Ying

On Tue, Jul 7, 2009 at 4:34 PM, Karl Dalen<no-reply at opensolaris.org>
wrote:
> I''m a new user of ZFS and I have an external USB drive which
contains
> a ZFS pool with file system. It seems that it does not get auto mounted
> when I plug in the drive. I''m running osol-0811.
>
> How can I manually mount this drive? It has a pool named rpool on it.
> Is there any diagnostics commands that can be used to investigate the
> contents of the pool or repair a damaged file system ?
>
> rmformat shows that the physical name of the USB device is:
/dev/rdsk/c4t0d0p0
> If I try ''# zpool import" I get:
> ?pool: rpool
> ? ?id: 3765122753259138111
> ?state: UNAVAIL
> status: The pool was last accessed by another system.
> action: The pool cannot be imported due to damaged devices or data.
> ? see: http://www.sun.com/msg/ZFS-8000-EY
> config:
> ? ? ? ?rpool ? ? ? UNAVAIL ?newer version
> ? ? ? ? ?c4t0d0s0 ?ONLINE
>
> I suppose this means that the data is corrupted in some way
> although I never observed any write errors when it was created.
> This drive was formatted with zfs by the osol-0906 installer.
>
> Another question is about backward compatibility of ZFS. If I create
> a ZFS system under say osol-0906 can I access this system on older
> nv builds and Solaris 10 ?
>
> Thanks
> /Karl D
> --
> This message posted from opensolaris.org
> _______________________________________________
> zfs-discuss mailing list
> zfs-discuss at opensolaris.org
> http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
>

Karl Dalen wrote:
> I''m a new user of ZFS and I have an external USB drive which
contains
> a ZFS pool with file system. It seems that it does not get auto mounted
> when I plug in the drive. I''m running osol-0811.
> 
> How can I manually mount this drive? It has a pool named rpool on it.
> Is there any diagnostics commands that can be used to investigate the
> contents of the pool or repair a damaged file system ?
> 
> rmformat shows that the physical name of the USB device is:
/dev/rdsk/c4t0d0p0
> If I try ''# zpool import" I get:
>   pool: rpool
>     id: 3765122753259138111
>  state: UNAVAIL
> status: The pool was last accessed by another system.
> action: The pool cannot be imported due to damaged devices or data.
>    see: http://www.sun.com/msg/ZFS-8000-EY
> config:
>         rpool       UNAVAIL  newer version
>           c4t0d0s0  ONLINE
Did you try this:

zpool import -f rpool someothername

I think there are two reasons it won''t import:
	1) It was last accessed by another system (or maybe the same
	 one but it had a different hostid at the time) so you need
	 to use the -f flag.
	2) There is probably another pool called rpool (the one you
	are running from), right ?

-- 
Darren J Moffat

On 08.07.09 12:30, Darren J Moffat wrote:
> Karl Dalen wrote:
>> I''m a new user of ZFS and I have an external USB drive which
contains
>> a ZFS pool with file system. It seems that it does not get auto mounted
>> when I plug in the drive. I''m running osol-0811.
>>
>> How can I manually mount this drive? It has a pool named rpool on it.
>> Is there any diagnostics commands that can be used to investigate the
>> contents of the pool or repair a damaged file system ?
>>
>> rmformat shows that the physical name of the USB device is: 
>> /dev/rdsk/c4t0d0p0
>> If I try ''# zpool import" I get:
>>   pool: rpool
>>     id: 3765122753259138111
>>  state: UNAVAIL
>> status: The pool was last accessed by another system.
>> action: The pool cannot be imported due to damaged devices or data.
>>    see: http://www.sun.com/msg/ZFS-8000-EY
>> config:
>>         rpool       UNAVAIL  newer version
>>           c4t0d0s0  ONLINE
> 
> Did you try this:
> 
> zpool import -f rpool someothername
> 
> I think there are two reasons it won''t import:
>     1) It was last accessed by another system (or maybe the same
>      one but it had a different hostid at the time) so you need
>      to use the -f flag.
>     2) There is probably another pool called rpool (the one you
>     are running from), right ?
I think this pool is just too modern for the system you are trying to 
import it on as it is UNAVAIL due to newer version.

Here''s an example:

root at jax # mkfile -n 64m version
root at jax # zpool create version /var/tmp/version
root at jax # zpool upgrade version
This system is currently running ZFS pool version 10.

Pool ''version'' is already formatted using the current version.
root at jax #
root at jax # rcp version theorem:/var/tmp

On the other host:

root at theorem # zpool upgrade
This system is currently running ZFS version 4.

All pools are formatted using this version.
root at theorem # zpool import -d /var/tmp
   pool: version
     id: 2589325003567752919
  state: FAULTED
status: The pool is formatted using an incompatible version.
action: The pool cannot be imported.  Access the pool on a system 
running newer
         software, or recreate the pool from backup.
    see: http://www.sun.com/msg/ZFS-8000-A5
config:

         version             UNAVAIL   newer version
           /var/tmp/version  ONLINE

root at theorem #


There''s a difference in messages though, but older host in my case is 
running Solaris 10 U4, so it may explain it. Anyway, I think pool 
version is the real reason here.

Victor

Thanks for the great tips. I did some more testing and
indeed it was a version issue. The pool was created under:
# zpool upgrade
This system is currently running ZFS version 14.

whereas I tried it on systems with versions 10 and 12.
It could be imported on a newer system using -f option.
I suppose it did not auto mount the pool because it
had the same name as existing pools. Is this a known
issue with ZFS ?

I assume because of this portability issue ZFS is not really suitable
for use on removable media such as USB drives that are intended to
be mounted on different hosts which may have different Solaris versions.
It may be better to stick with UFS for this case.

/KarlD
-- 
This message posted from opensolaris.org