Storage Drives of Multiple Sizes?

[pchidley]

Sorry for the newbie question but couldn't find an answer.

Some NAS systems require that all storage drives be the same size. E.G. 2TB

Is this a limitation of FreeNAS or can I have 2TB and 8TB mixed?

 

[ljvb]

You can mix and match drive sizes in the overall pool, but they need to be in separate vdevs. Group same, or very close in size drives in each vdev, you will loose the least amount of storage space that way.

 

[pschatz100]

If you mix drives in the same vdev, the capacity of the vdev will be determined by the smallest drive. So for instance, let's say you make a three disk vdev configured as RaidZ1, using two 2TB drives and one 8TB drive. The raw capacity of the vdev will be 4TB - just the same as if you used three 2TB drives. Everything will work OK, but you don't get any benefit from the larger drive.

Hopefully, this makes sense. Read the stickies about configuring vdevs and pools to understand why this is so.

 

[sretalla]

If you don't care about your data, you can elect to create a striped pool with any number of disks of any/mixed size and you will get the total amount of all the disks available in the pool... without any redundancy or possibility of correcting errors if they are found.

If that level of risk suits you (remembering that one single disk failure loses all the data on all disks in that pool), then it can work as it seems you want it to.

This does, however mostly defeat the benefits of having ZFS, while still working with the penalties like RAM requirements, so maybe you want to consider one of the other Linux-based alternatives.