Media setup with Expandable RAID reccomendations?

[jimmypooh]

I need a recommendation on what RAID to run in my setup that will allow for future expansion.

I've been running FreeNas (8.3 currently) for a year with 0 problems! I built a dedicated unit last year (dual core 3.2 with 8GB ram) and have a single 2TB drive that is now full. I've recently purchased 4 x 3TB drives. I would like to get to a point where I can continually add drives (of various sizes if possible) to expand my storage space when I need them. I would like all space to show up as one drive without nested drives/folders (meaning I don't just want to add a new folder that can have up to 3 TBs in it). Speed isn't important to me so I don't think I need a Raid0 of any sort but the RAID0 does put all storage into the same place. I have a spare machine that I could use as a second NAS machine to take backups instead of using mirroring.

It is my understanding that most (possibly all) ways that I could run RAID would not let me use different size drives freely. I would like it if when one drive got full, it just started using the next drive without me having to go to a different location. Is anything like this possible? Thanks for the help!

Jim

 

[jimmypooh]

I've been reading more and was thinking I will add another vdev to my zpool. Will that be a problem since the first vdev is full? Will it restripe evenly to the 2 vdevs? Would you recommend a second (slow NAS) to back up as opposed to parity or is that overkill...just parity and don't worry? Thanks!

 

[louisk]

I would strongly caution you to spend a bit of time understanding the implications of what you are proposing before you do anything.

You can't remove drives from a pool one added. Additionally, if you add a single drive, as opposed to a redundant (raidz, raidz2, mirror) you risk the pool on the life of that single drive (if that drive dies, so does all your data in the pool).

I would suggest that you do something like:
Setup 4x3T in raidz (gives you more storage, could also do raidz2, or mirrors), put it into a different pool, move the data to the new pool, destroy the old one and then remove the old disk. When you run out of space, buy bigger disks and replace the existing disks. Don't keep adding things to the pool.

 

[jimmypooh]

That's great advice and I will likely be doing just what you said. Is is considered high risk if I run a raid-z without a full backup of the data outside of this box? I would prefer not to have to double my hardware if I can help it. I will have an offsite backup of my critical data but not all of my media.

 

[louisk]

Only you can answer that question. You have to think about the value of the data and your ability to recreate it from scratch. If you already have a backup, the difference in cost of a few T in space is pretty small.

 

[paleoN]

Personally with 3TB drives I would only mirror them or run double-parity, raidz2.