[OpenIndiana-discuss] System Panics after deleting zvol - Work Around

[matt at focusedmobile.com]

   Thanks George and Jim (anyone else if I missed you)for all the help 
and great ideas. I also received a lot of help from Ryan W. who you see 
on the original thread I posted at the Nexenta forums.  With some help 
from Ryan I was able to locate a 5 month old snapshot after I mounted 
the pool as R/O.  I then setup a new pool on two HD's approx 3TB usable 
space and then used the zfs send command to copy over the data from the 
snap, it took the good part of a day, almost 2TB of data to copy but I 
was able to map it via iSCSI back to my windows host and all my data is 
there.  Well only missing 300 GB of stuff over the last five months, 
most important I copied off some of the more important personal data 
(old tax forms etc) I didn't want to lose.. one reason I put my 
important data on ZFS was knowing it was protected by a file system I 
could trust and won't not rot away.  This issue I ran into I admit is 
solely my own responsibility since I was playing around with dedupe on a 
system that couldn't handle it (not enough memory).  Now with the 
confidence I have running the zfs send, I'm going to delete the zvol and 
try to copy the old pool over using the dd command to recover the whole 
zvol, if it doesn't work then not all is lost. Now I only want to gain 
the experience and prove to myself I can recover all of the data using 
dd.  Great community, thanks for allowing me to bother you guys.. Might 
be switching over to OpenIndiana with Napp-it since after getting a 
little experience with your live CD I am starting to really like it.

Matt

> ------------------------------
>
> Message: 7
> Date: Fri, 09 Nov 2012 09:52:12 -0500
> From: George Wilson <george.wilson at delphix.com>
> To: openindiana-discuss at openindiana.org
> Subject: Re: [OpenIndiana-discuss] System Panics after deleting zvol
> Message-ID: <509D189C.3090409 at delphix.com>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
> Matt,
>
> You should do something like this:
>
> 1). zpool create <newpool> <newdisk>
> 2). zfs get -o name,value -p volsize <oldpool/oldvolume>
> 3). zfs get -o name,value -p volblocksize <oldpool/oldvolume>
> 4). zfs create -V <value from step #2> -b <value from step #3>
> <newpool/newvolume>
> 5). dd if=/dev/zvol/rdsk/<oldpool>/<oldzvolume>
> of=/dev/zvol/rdsk/<newpool>/<newzvolume> bs=128k
>
> Once the 'dd' completes then you can configure the newzvolume to 
> share
> out with iSCSI and try it out.
>
> Good luck,
> George
>
> On 11/8/12 7:32 PM, matt at focusedmobile.com wrote:
>> Are you able to create a pool on another disk? If so, then you could 
>> try
>> to create a new zvol on the new pool and copy over the contents from 
>> the
>> old zvol using 'dd'. Then you could try to share out the LU from the 
>> new
>> pool.
>>
>> - George