Resilver or Rebuild z2 array?

[jlpellet]

Earlier this month, I built a 5x4TB Z2 array on one of my FreeNAS servers, using 3 Seagate & 2 WD NAS drives. Unfortunately, this was before WD admitted shipping SMR Reds. In building the array, I noted very slow & variable write speeds when copying the 7.5TB of data to the array (from another server, over 1GB ethernet). Because I understand how unlikely a resliver of the WD's is, I plan to replace the SMR drives (will reuse on desktop drives which do very little sustained writes) with CMR.

My question or advice request is which of the following options is recommended 1) offline both WD, power down, replace both, then resilver both or 2) wipe the array, replace the drives, then copy all of the data back. I have no experience resilvering with 2 replacement drives, but, based on my reading, worst case if #1 fails, #2 would be the backup.

Note I cannot but both new drives in then resilver with the existing drives in place (not enough drive bays or slots) &, given I have to move the server to replace drives, I don't want to do 1 at a time. I am not concerned about data loss as I multiple online data copies on the network.

Any comments of suggestions are appreciated.

I don't think it matters in this case, but this is an AMD A6, 8GB RAM system from circa 2013, running 11.3U1, booting from 64GB SSD

Thanks,
John

 

[Heracles]

I don't want to do 1 at a time.

That would have been the safe way...

I am not concerned about data loss

Ok... Then I would re-do the entire pool. Destroy the actual pool, replace the SMR drives and create a brand new pool. That way, you clearly what you are up to and that your pool will be destroyed / its content will be wiped.

Should you try to do 2 drives at once and something goes wrong, the end result may be the same but not as directly expected as destroying the pool yourself.

So I would be honest with myself here : Destroy and re-create.

 

[jlpellet]

FYI, I replaced both SMR disks & the system reported a successful resilver of 5.23T in 11:41.