Questions about ZFS

[ruffpl]

I am thinking about building NAS and have couple of questions because I never tried ZFS. I want to put 2 ssds as system disk in ZFS Raid1 and to keep my data on f.ex 4x3tb drives in ZFS pool ( all hdds will be connected to mainbord/ not pcie sata/sas controller)..
Can I easy expand it over time and add another 3tb drive to have more space in it (like in Synology SHR)? It will grow up in a simple way, its hard and have to do it manually or it is not possible?
Another question. What will happen if there will be some problem with my server f.ex system, mainboard, etc will crash. Is data and ZFS pool will get damaged, whether the data and pool will be completely secure and and nothing will happen to them once the new system will be created ( are all settings of pool are on hdds, or on system)?

 

[Kris Moore]

Couple thoughts:

1. If you are doing two disks for your system pool, you are better off mirroring them, raidz1 won't be of any value here.

2. If you have 4x 3TB drives, you'd need to add another group of 4 drives to make a complete new "vdev" to expand. If you instead did a pool of mirrors, I.E. 2x 3TB Mirror Vdev + 2x3TB Mirror Vdev, you'll end up with 6TB usable, but you are able to expand by adding another 2x 3TB drives in the future.

 

[ruffpl]

Thanks. I would like to have as much space it is possible with a option of one disk failure ( there will be external backup) and option of snapshots ( to restore files if they will be deleted, broken or something). It will be just media home server not for webhosting for someone, etc.
Is there some option in ZFS similar to Synology SHR on BTFRS? Lets say I want to create one big "volume" ( that data is safe on it, with snapshots and option to enlarge it), or couple of "volumes" from hdds f.ex one 20tb for movies, second 10tb for music, etc. Which option will be the best for me?

 

[sretalla]

Is there some option in ZFS similar to Synology SHR on BTFRS?

No

Which option will be the best for me?

The option suggested by @Kris Moore is the best currently available.
In some far-off version of the future, what you're asking for may finally arrive on FreeNAS (in some kind of version that will allow RAIDZ1 volumes to be expanded by 1 disk at a time), but don't hold your breath.
Maybe FreeNAS isn't for you... perhaps unRAID or OpenMediaVault are better candidates to match what you want.