Question Regarding Diferrent Drives Sizes in Group/Volume

[muchoman90]

Hello Guys,
I've just started messing around with FreeNAS a couple weeks ago and I love it. Right now I have a single drive as a volume since it was for testing purposes, so I do not have much experience with RAIDZ. I've decided I want to build a rig specifically for FreeNAS (for home media use). I currently have 2 3TB WD Red drives and was going to buy a 3rd one so that I could put the 3 drives in a RAIDZ Volume. But before ordering the 3rd drive, I thought about using 5TB WD Red drives instead. So my questions are:

1) Would a RAIDZ with 2 3TB drives and 1 5TB drives have the same usable space as a RAIDZ with 3 3TB drives?
(I'm almost certain the answer to that is yes and I'm ok with that, but wanted to double check)

2) Would it be a reasonable/possible plan to get a 5TB anyway and do the following:

Create a RAIDZ with 2 3TB drives and 1 5TB drive
and then in the future (when I have more money),
add another 5TB drive to the RAIDZ (at this point have 2 3TB drives and 2 5TB drives in the volume)
then remove one of the 3TB drives (at this point have 1 3TB drive and 2 5TB drives)
sell that 3TB and use the money to get another 5TB drive
add the 5TB drive to the volume (at this point have 1 3TB drive and 3 5TB drives)
then remove the 1 3TB drive (at this point have 3 5TB drives and have full usable space of the 5TB drives, minus parity)

The other option I could think of is to get a 3TB drive
build the Volume with 3 3TB drives
and in the future, when I can afford it
get 3 5TB drives,
make a 2nd volume with it
copy the data from one volume to the other
then sell the 3TB drives.

The problem with that is, it's much harder to afford 3 5TB drives at one time.

What are your opinions/suggestions?

 

[muchoman90]

Hey Guys,
I've decided to use the 2 3TB drives as 2 separate (non RAIDZ) volumes and since they're not in a group together, use a diff brand 3TB drive (that I had laying around) as a 3rd separate 3TB drive. I'll get all the data off my Synology NAS and onto this test run of FreeNAS, sell the Synology NAS and then use that money to help afford the parts I want to use to build a proper FreeNAS rig. Once I've got the new rig setup, I'll move the 3TB drives to it and work on getting some 5TB drives for a RAIDZ. Move the data from the 3TB drives to the RAIDZ volume and then sell the 3TB drives. The only issue I'm having is that FreeNAS refuses to see the 2nd 3TB drive as an available disk to create a volume with. I'll create a separate post for this issue though.