Upgrade+install to new device: import old config or pool first?

[guermantes]

Hi!

TLDR:
After successfully installing 11.2-U3 to a new device (having had the pool drives disconnected during the install), does it make a difference whether I import the old pool first or whether I import the old config first?

Long version:
I am currently on 11.0-U4 and have decided it is time to finally move to 11.2 (i.e. U3). I will use the occasion to stop having Freenas on a USB-key and put it on an SSD, so I will be performing a fresh install on the SSD (and keep the USB-key with 11.0 in case I need to revert back).

I will of course save the current config.
Before installing, I plan to disconnect all drives except for the system drive SSD (since there were hickups with pools disappearing previously...I know there is a fix to be more careful with rm but just the same...).

Now, after successfully installing, does it make a difference whether I import the pool first or should I import the config first?

 

[danb35]

I'd import the config. It will reboot the system (twice, IIRC), and should import the pool on boot.

since there were hickups with pools disappearing previously

The issue was with data disappearing. Disconnecting the pool drives isn't a bad idea. Taking a recursive snapshot of the entire pool is also highly recommended.

 

[guermantes]

Disconnecting the pool drives isn't a bad idea.

Just to make sure... you didn't mean to say "isn't a good idea", right?

Taking a recursive snapshot of the entire pool is also highly recommended.

Yep! I have one, and it's been replicated to an offline drive as well.

 

[danb35]

Just to make sure... you didn't mean to say "isn't a good idea", right? :)

No, I mean "isn't a bad idea." Leaving the pool drives disconnected while you do the upgrade makes it much harder for whatever's occasionally trashing data to do so. I don't think it's necessary, particularly in light of the fact that snapshots completely mitigate the issue, but it's another layer of precaution.