Best practice for removing a drive from one pool and replacing a faulty drive in another pool ?

[ethereal]

I have 2 pools both RaidZ2 - Storage has 6 x 3 tb and Working has 4 x 3 tb.
I have two blue discs in the Storage pool which I tried to turn off the head park - but failed they now are both over 450,000 (load cycle count). I was obviously worried and kept an eye on them.
One of the blue drives started to display smart errors and i ordered an 8 tb replacement. Now the drive has failed a short smart test.

The bad drive is in Storage (along with another blue - which has no problems apart from 450,000 LCC) - obviously I am worried that the other blue drive could start playing up threatening my data.
So I would like to get a replacement in there as soon as possible.

The replacement disc won't be here until thursday - and then I have to run badblocks on it. It could be 10 days even before I add the disc to the pool and start scrubbing.
As there are 6 discs to replace in Storage before it expands the pool size (and a potential problem with the other blue drive). And there are only 4 to replace Working to expand the pool.
What I want to do is remove one of my discs from the Working pool and use it to replace the faulty blue drive in Storage.

What is the best practice for removing a drive from one pool and replacing a faulty drive in another pool ?

Thank you

 

[kdragon75]

If you don't need access to the dying drives just shutdown and remove the power, then boot back up and keep using the good pool until you can replace the drives. Don't risk killing both pools for a 2 week patch.