Attach mirror drive to pool

[RandomFactoid]

Hi,

purely from the curiosity of hobby'ism, I managed to pick up a Microserver Gen8 for a good price to replace my Rpi4+external USB drive.

The setup atm is as follows:
-Microserver Gen8 with Celeron 1610T (will upgrade to one of the Xeon E3's soon)
-12gb ram
-Running ESXi with Truenas Core VM
-1x 4TB WD Red (/dev/da1) with data in stripe pool called Red4

I now got another empty 4TB WD Red that I want to mirror my data to from Red4.


After doing some reading there seem to be several ways to do it and i'm a little confused. Some say to attach the new drive to my existing pool via shell by using zpool attach, some suggest creating a new pool via GUI and proceeding from there.
I haven't yet tried either of those as I'd like to get it right the first time. I suppose the best option would've been having both drives in from the beginning, however one of them had the data and I had no way to backup to be able to start off with 2 clean 4TB drives.

Thanks for your advice

 

[sretalla]

If I understand you well, you want both disks in the same pool (in a mirrored configuration), holding the same data.

There's nothing wrong with that happening after pool creation (it's only with RAIDZ pools that it's a problem).

You can do it in the GUI:

(having first installed the second disk in the machine and rebooted if necessary... maybe you have hot-swap)

Under Storage | Pools

Click the cogwheel for the Red4 Pool, select Status

Click the 3 dots to the right of the existing disk in the pool and select Extend (that's really the wrong word here... it should be attach... , but it's the right option)

Then select the new empty disk and confirm... then your new disk will become part of a mirrored VDEV together with the existing one and resilvering will start (to make the disks equal in content).

 

[spg900ny]

...then your new disk will become part of a mirrored VDEV together with the existing one and resilvering will start (to make the disks equal in content).

I just wanted to say thanks for your reply to OP. It was a huge help to me as I knew I had read somewhere that you could do this now in the GUI, but I couldn't find info on it anywhere else. For that reason I was a little leery about trying this (also because I had stupidly in the past accidentally expanded a volume when meaning to add a mirror), but I had a backup, so I figured I'd try it. Made me really happy to see that "MIRROR" label when it was done. Cheers, and thanks again.

 

[Stux]

Click the 3 dots to the right of the existing disk in the pool and select Extend (that's really the wrong word here... it should be attach... , but it's the right option)

Still a stupid name for the option. Just got bitten again "no, I don't want to extend the stripe... I want to add a mirror disk to it... where's the attach option, afterall I just used 'detach' and want to reverse it...

 

[Frank Collins]

Still a stupid name for the option. Just got bitten again "no, I don't want to extend the stripe... I want to add a mirror disk to it... where's the attach option, afterall I just used 'detach' and want to reverse it...

Did you ever get a fix for this?

 

[sretalla]

Did you ever get a fix for this?

No fix is really required since the menu option is there (just labeled in a way that may confuse some people).