Backing up zfs system to external disk

[Mike Clarke]

On Saturday 26 July 2014 16:27:56 CyberLeo Kitsana wrote:

> Set canmount=off or noauto on the backup datasets. Beware that this
> property is not inherited, so you must explicitly set it on every
> dataset for which you wish to avoid auto-mounting.

I'd already thought of this but prefer not to do it.

The backup script would need to search through all the datasets 
changing the canmount properties of all mountable filesystems. The 
backup pool would no longer be an exact copy of the working system and 
would need manual changes to be made before it could be used for 
recovery. I'm using multiple boot environments created with 
sysutils/beadm so there's already a lot of datasets with 
canmount=noauto. It wouldn't be a simple case of just resetting all 
"noauto"s back to "on".

By keeping the backup pool as an exact clone of a system snapshot 
recovery will just be a case of using zfs send | zfs receive to copy 
everything from the backup pool to the system pool. In fact if the 
system disks were totally trashed I could even boot directly off the 
backup until replacement disks arrived.

-- 
Mike Clarke