What could I do with more drives?

[Something]

I currently have a WD Red 4TB in my NAS (entirely used for storage for backups) and was thinking of expanding since 4TB seems like it might not allow for as many backups as I like. What could I do with 1-2 more drives?

 

[danb35]

• You could add one or two disks to your pool by striping them. This would give you maximum capacity and performance, but no redundancy--if (when) any one disk dies, you'd lose your whole pool.
• You could add any number of disks as individual zpools (volumes). This would also have no redundancy, but when one disk fails, your remaining disks (and data) wouldn't be lost.
• You could add a disk as a mirror of your existing disk (which would require some work at the CLI). This won't give you any more capacity, but it will give you redundancy.
• You could create a three-disk RAIDZ1 volume. This will give you greater capacity and redundancy, but you'd lose your existing data in the process unless you had it backed up somewhere else.

 

[Something]

I think I'll hold off on RAIDZ1 for now, until I can do a RAIDZ1+0 (or equivalent) setup with 6 disks.

I'm leaning towards redundancy, reduce downtimes and safeguard legacy backups. If I were to go with two individual volumes can they be setup such that when one volume is full, backups go to the second volume?

What would you recommend?