Accidently killed my zpool, can i recover?

[onthax]

So i was migrating from physical freenas to hosted on esxi. all going well.
my plan was to break my raid10 zfs pool, install drives on the machine, zfs send the datasets accross, move the other disks and recreate the mirror
.

Configuration was

pool
mirror 0
disk 1
disk 2

mirror 1
disk 3
disk 4

So I take disk 3 and 4 , put it in my new virtualised freenas box, create a new pool on it using the gui.
go to send the zfs dataset accross, get a bunch of errors.

So i looks like i broke my system.

disk 3 and 4 were a mirror of 1/2 of the stripe.

looking like i lose 4.5tb of data :^(

My question, is there any way to recover from a overwritten zfs disk?

 

[ghostlobster]

I just went through something similar, but not identical, and was able to recover a lot of data. The circumstances differed greatly, however, so I doubt that what worked for me would work for you, but it's worth looking at.
If you just do a zpool import from a shell, what gets displayed? Don't worry, it's not going to change or overwrite anything, but it will definitely help in seeing if there's something there salvageable.
Also, take a look at this thread which documents my near catastrophic failure, and the steps paleoN walked me through:
http://forums.freenas.org/showthread.php?9280-FreeNAS-8-3-Will-Not-retain-ZFS-Pool

 

[paleoN]

The circumstances differed greatly, however, so I doubt that what worked for me would work for you, but it's worth looking at.

It won't. This is a completely different failure mode.

So i looks like i broke my system.

You did.

looking like i lose 4.5tb of data :^(

Restore from backup?

My question, is there any way to recover from a overwritten zfs disk?

Manually, if you have the necessary information and skills. You can likely recreate the basic ZFS label information from the zpool.cache file. The trick is then to create the appropriate uberblock in the label pointing to where it's supposed to point. Such is certainly beyond my skills and beyond yours if you have to ask.

 

[onthax]

It won't. This is a completely different failure mode.

You did.

Restore from backup?

Manually, if you have the necessary information and skills. You can likely recreate the basic ZFS label information from the zpool.cache file. The trick is then to create the appropriate uberblock in the label pointing to where it's supposed to point. Such is certainly beyond my skills and beyond yours if you have to ask.

Hmm, will give it a bash, nothing to lose.

They, will restore from backup, i think 3 months ago is latest backup. all the essential stuff is there, mightve lost a little. will see. Most importantly, photos are offsite backup!