Can I improve redundancy building multiple RAIDZ1 pools and combining them together?

[mhweb]

I'm building my first FreeNAS server to store data and use Plex, and knowing that using RAIDZ2 can only protect you from two disk failures and it's not possible to expand the array one drive at a time, is it a solution to create multiple RAIDZ1 pools with a minimum of 3 drives and expand the storage using the vdev expand feature? If I have a storage made of multiple drive pool, if I lose one of the RAIDZ1 pools will I lose all the data on the entire server or just that one RAIDZ1 pool?

 

[MikeyG]

Your pool is made of vdevs. If you have multiple RAIDZ1 vdevs combined to form a pool, then each vdev can sustain 1 drive failure without bringing the pool down. If you have 6 disks, and you create 2X RAIDZ1 vdevs to form your pool, that gives you less protection than a single RAIDZ2 vdev with all 6 disks. You can not expand a vdev. You can only expand a pool by adding vdevs.

 

[mhweb]

Thanks for the info, and clarification.

 

[mhweb]

Do you know if there's an alternative to start with, for example, with 40TB, and down the road upgrade the storage with the least amount of drives and having one pool using the current features in FreeNAS?

 

[MikeyG]

If your goal is media storage, and you want the protection of RAIDZ2 (which is highly recommended), then the only option is to create a pool with a single RAIDZ2 vdev, and then add another vdev to that pool later.

For example, if you have 8 drive bays in your server, you might get 4X 10TB disks to start with and create a RAIDZ2 based pool out of them. Later, get 4 more drives, add another RAIDZ2 vdev, thus doubling the space. That config should start you off with roughly 16-18TB usable space. Adjust disk size, number of disks, etc accordingly to meet your goals.