Adding a third drive

[reudant]

I have a feeling that this question has been asked before but I couldn't find it anywhere. I have a two 3 TB drives mirrored FreeNAS setup with data on the drives. I have added a new 3 TB drive to the computer. I cannot figure out how to add that drive to the existing setup. When I initially ran the Wizard setup, I had the Wizard select the best option for the two drives I had installed. I think it is mirrored. I'm guessing the Wizard went with media (Raid Z1) option. I'd rather not destroy the data to change the configuration of the raid. I'd like to stick with media Raid Z1 but if I have to go with backups Raid Z2 then that would be fine. I can't figure out how to do this. The guide isn't helping. I need some step by step instructions.

 

[SweetAndLow]

You will have to destroy your pool. This is explained all over the place. You can't turn a mirror into a raid z. You also don't want to use raidz1 with 3tb drives. Raid z2 is the sweet spot.

Sent from my Nexus 5X using Tapatalk

 

[gpsguy]

Another thing you could do is buy yet another 3TB drive and add a mirrored vdev to your existing pool.

As SweetAndLow said, RAIDz2 would be a sweet spot for you, but growing a pool using mirrors might be easier to do if you can't afford buy all the needed disks up front. There are some tradeoffs between mirrors and RAIDz1, 2, etc. - see the docs and/or search the forum for cyberjock's guide.

 

[reudant]

You will have to destroy your pool. This is explained all over the place. You can't turn a mirror into a raid z. You also don't want to use raidz1 with 3tb drives. Raid z2 is the sweet spot.

Sent from my Nexus 5X using Tapatalk

Thanks for your response.
When you say destroy the pool, you mean destroy the data that's in the pool? (I don't really understand what I'm doing.) I think I added the drive to the mirror as stripped? This is what Freenas shows me now: <pic>

 

[SweetAndLow]

So now you have that single drive as a point of failure. This is fine but probably not what you wanted to do. To fix this you will have to backup all your data and rebuild the pool. There was a big warning telling you this when you did this so I'm assuming you knew what you were doing.

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[gpsguy]

You could also add another (new) 3TB drive and mirror the one you just added. Unfortunately that would require you to use the CLI and I wouldn't recommend *you* doing it. Follow SweetAndLow's advice.

 

[Stux]

So, assuming you have want redundancy, you have three options.

1) add a fourth drive to mirror the third drive.
2) backup the contents. Destroy the pool and recreate it as 3 way raidz1
3) add a fourth drive, backup the pool, destroy it and recreate as 4 way raidz2

1) is probably best, and if you don't mind 50% redundancy will allow you a good growth path in Future.