Best strategy to replace drives?

[djidji perroto]

I'm running a small 4-bay system with 2 mirrored 4TB drives containing most of my data (incl. system dataset) and 2 striped 750GB drives containing some recoverable files.
One of my 4TB drives failed with bad sectors and I bought 3x 6TB WD Reds to use as a RAIDZ1.
What would be the best strategy to move data from the old drives to the new ones?
I've identified 2 paths
- export/offline the striped pool
- disconnect 750GB drives and my failed 4TB
- use the now available 3 sata ports to connect new drives and build a new RAIDZ1 pool
- migrate degraded pool to new pool
- I can then proceed to play with ideas how to migrate the not-so-important data from my stripe pool (i.e. fail one of the RAIDZ1 drives temporary, re-import, migrate, etc...)
The issue I have is I read somewhere I'll need to move the system dataset off to a new/different pool and I'm not sure how to do that with my current limitations.
Option 2 would be to add the 3 new drives to a new vdev (z1), then add the vdev to my degraded pool, then somehow migrate the data from now single-drive vdev and remove it from the pool. Not sure this would be possible or how to do it...
Any suggestions?

 

[SweetAndLow]

Are the striped disks part of the same pool at the mirrored disks? Can you provide the output of zpool status in code tags?

 

[djidji perroto]

Striped disks and mirrored disks belong to different pools and I really, really don’t care about the striped disks at this stage

 

[SweetAndLow]

Ok so your option 1 you gave above is a good idea. Or you can just add 2 if your 6TB disks as a mirror to your existing mirror vdev and make a pool with 4 disk, 2 in each mirror. Then replace your failed disk with your other 6TB.

How many sata ports do you have? Maybe there are other options but your kinda limited without some way to offload your data to another pool.