Best practice for increasing storage raidz1

[wags22]

I'm working on increasing the storage on my Truenas system. Currently I'm running 3 x 2 TB WD Red and want to add 3 x 4 TB WD Red. I've perused the forum and some help articles and have some questions about how best to proceed. I can't create a single pool with the different drive sizes, right? But can I create multiple pools under the same filesystem? Would it be best/possible to shutdown the system, install the new drives and build out a "new system" and then add the old drives, recover the data, and then rebuild the old drives? Only other option I can think of is to replace the old drives one at a time and wait for the resilvering to take place (been there, done that when I upgraded from 1 TB to 2 TB drives, rather not do it again.)

My system is the home of my plex server as well as a few VM's. I'm ok with building out a new plex server and just copying the data over (would probably solve some other problems I'm having).

 

[Etorix]

If you have enough ports to attach all drives, the easiest way would be to create a new raidz1 vdev with the the new drives and add it to the pool. 2*2TB + 2*4TB available. But ZFS will not rebalance the data between vdevs.

Of course, you can also create a new pool and replicate data from the old to the new pool. This is the opportunity to change geometry.
Raidz1 is not very secure, and becomes less secure as drives get larger. The media collection would be safer on raidz2—requiring four drives. Raidz, in any version, is not suited to VMs, which would best be on mirrors.

The path to success for block storage

It seems like I haven't written a sticky for awhile, but just in the last week I've had to cover this topic several times. ZFS does two different things very well. One is storage of large sequentially-written files, such as archives, logs, or data files, where the file does not have the middle...

www.truenas.com

Consider creating a new pool with at least four drives in raidz2, and reusing the old drives as a mirror in another pool for VM.

 

[ChrisRJ]

Do you want to replace the existing drives and by that have your pool underpinned by single RAIDZ1 vdev like before (but with the net capacity increased from roughly 4 TB to roughly 8 TB)? Or do you want to create another RAIDZ1 vdev out of the new disks and add that capacity (around 8 TB net) to the existing pool (ending up with around 12 TB net capacity)?

 

[wags22]

Thank you for the quick responses.
What I was finding when perusing was that I should move away from RAIDZ1 which I'm fine with. My ultimate goals are 1) Increase the storage capacity (I'm at 80% right now). 2) Hold onto the data I have, not concerned with the VM's now or in the near future. They're a nice to have, not a necessity. I can live with them running on a non-mirrored system.

Unfortunately for me, I purchased new drives without doing my research first. If I want to go to RAIDZ2 then I need to have 4 drives so I'll have to order another.

One more question/thought (thinking out loud) before I place that order: 1) If I read the documentation correctly, I can scrap my current build and start over, and be able to import the pool on the current drives. If I don't want spend the extra money to add another 2 TB drive, then I can leave that pool alone until I'm ready to "upgrade" again?

I feel like I have more questions, but I can't sort my thoughts at the moment.