# Zfs nas



## niclas197 (Oct 11, 2009)

Hi guys,
I'm going to build up a NAS system based on FreeNAS (which is FreeBSD 7.2) with the following hardware:

Asrock A330GC â€” Intel Atom 330 Dual Core
2 Gigs of RAM
a standard ATX case (I think that I can use it for Mini-ITX as well)

and two Western Digital harddrives (1,5 or 1 TB)

my preferred filesystem is of course ZFS 

So my question is if I can create a virtual device including both devices (let's say vdev0) as a Raid Z and add one or two hard disks at a later time to that device. Of course Raid Z with 2 devices is just a mirrorâ€¦

Or is there any better solutionâ€¦ I would also really appreciate some hints at configurations with different drive sizes (for my old drives with noting to do  )

My second question is if ZFS makes sense on such a low powered device?

Thank you for your time


----------



## vermaden (Oct 11, 2009)

Try FreeNAS (FreeBSD based):
http://www.freenas.org/

It includes ZFS support.

Does it makes sense?

Yes, why not, you have a lot of RAM, you will have slow transfer if you wpuld want to use GELI, but ZFS itself will work without problems here.


----------



## DutchDaemon (Oct 11, 2009)

niclas197 said:
			
		

> I'm going to build up a NAS system based on FreeNAS (which is FreeBSD 7.2) with the following hardware



FreeNAS is _based on_ FreeBSD. They are not the same.


----------



## vermaden (Oct 11, 2009)

@niclas197

I have just read your post again, you mentioned FreeNAS in the first place, I think I need some sleep


----------



## phoenix (Oct 13, 2009)

niclas197 said:
			
		

> Hi guys,
> I'm going to build up a NAS system based on FreeNAS (which is FreeBSD 7.2) with the following hardware:
> 
> Asrock A330GC â€” Intel Atom 330 Dual Core
> ...



raidz1 vdevs require a minimum of 3 drives.
raidz2 vdevs require a minimum of 4 drives.

With only 2 drives, you are limited to a mirrored vdev.

You cannot "expand" a raidz vdev by adding drives to it.  You can increase the capacity of a raidz vdev, though, by swapping 1 drive with a larger drive, doing a "zfs replace" on that device, letting it resilver, and repeating until all drives in the vdev are replaced.  After that, a "zpool export" and "zpool import" will make the extra space available to the pool.

You can "expand" the disk space for a pool by adding more vdevs to it.  I believe there's currently a limitation where all raidz vdevs in a pool must be configured the same (all 3-drive raidz1, or all 6-drive raidz2, etc).

So, if you have 2 drives, you can create a mirrored vdev, and add that to a storage pool.  Later on, you can buy 2 more drives, create a mirrored vdev, and add that to the existing pool.  And repeat as needed.



> My second question is if ZFS makes sense on such a low powered device?



CPU power is only really needed if you enable compression, and only if using gzip compression.  Using lzjb compression won't add much CPU use.  No compression should run just fine on the Atom.

RAM is the most important feature for a ZFS system.  The more RAM you have, the better things work, as you can create a larger ARC.

64-bit support is needed for the most stable configuration.  You can use 32-bit FreeBSD with ZFS, but you have to do a lot of manual tuning of /boot/loader.conf, and you will run into lockups over time.  If possible on that CPU, install the 64-bit version of FreeBSD.


----------

