Mirror Existing Pool

[JCasanova]

Hi everyone!

I have an existing ZFS Pool. It consists of 2x 2TB drives that are striped.

I have installed a 4 TB drive that I would like to use as a mirror for the existing pool.

My purpose with this is to make a copy of my existing data so that I can set up a RAIDZ2 using the 2x 2TB drives and a future purchase of 2 more 2 TB drives and to provide a level of redundancy for the current data storage.

This is not a production machine although I'd prefer to not lose the data.

How do I set up the 4 TB to mirror the existing pool? Would I be better off setting up a local replication task? I'd prefer something that is more of a "live" mirror than replication provides.

 

[cyberjock]

In short, there is no way to mirror your pool. You can setup a sort of backup routine using replication tasks, and that's exactly what I would do in your situation.

Even if you could create the pool from scratch the most you can hope for is to mirror one of the 2TB drives in a single vdev (you'd only have 2TB of total disk space available to use).

Keep in mind that you should keep snapshots for a reasonable period of time (I'd recommend at least 2-3 weeks). The reason is that if the primary pool starts having corruption that corruption *will* be replicated to the backup pool, so you'll need to be able to roll back to a snapshot that isn't corrupted.

 

[JCasanova]

I do have another option now that I think about it.

I can throw the 4 TB into another machine and replicate between it and the current FreeNAS box as sort of a "hot spare".