Re: [PLUG] FreeNAS vs. Debian for my simple home NAS

[Chris Heerschap <ChrisMH@AWeber.com>]

I've got quite a bit of experience with FreeNAS in the past six or so 
months, have done some extensive testing with it, we'll probably use it 
here at work at some point, but in the meantime I was so impressed with 
it (and ZFS) that I just set up my own FreeNAS/ZFS server at home.

Some things:

* FreeNAS is wonderfully easy.  I had the system out of the box and up 
and running as an NFS and CIFS server in under an hour.

* ZFS is really, really amazing.  Roll mdadm, LVM, and a filesystem all 
into one, and give you some seriously impressive tools with 
snapshotting, compression, encryption, and remote replication. (just to 
name a few) All of this is managed with only two commands, which I've 
found pretty straightforward considering the capabilities that are provided.

* Yes, ZFS loves RAM if you've got it.  I set up my server with 16GB 
because RAM's pretty cheap.  Paid a little more for ECC.  It can be used 
with less.  All depends on how much you really need it to do.  Have a 
single-drive system running as a simple NAS in our LAB with 4G of memory.

* Don't bother with ZFS if you can only run 32 bit code.  64 bit only.

* Dedup - don't do it.  I can't tell you how much time I've spent with 
ZFS dedup (because I don't want to think about it) and the conclusion is 
yes, it works, but the caveats are pretty major, and if you don't have 
the hardware to support it, you do NOT want to see how slow it can go.

* Yes, ZFS wants no hardware RAID, so it can manage the drives directly.

* ZFS does _NOT_ require RAID or mirroring.  You can run it on a single 
drive just the same way you can run mdadm/LVM/ext4 - and you are in the 
same boat if that one drive fails.  During testing, I've set up an 8 
drive stripe - that's zero redundancy, "RAID 0".

* RAID-Z2 is not mirroring.  Mirroring is mirroring, RAID-Z2 is the 
equivalent of RAID-6 (two parity drives).  RAIDZ (or Z1) is RAID-5 
(single parity), and RAID-Z3 is three parity drives, I don't think 
there's an equivalent in conventional RAID.

* Uncertain about how a ZFS NAS needs "2 boot disks and 8 data disks", 
that's pretty arbitrary, especially considering FreeNAS runs the OS off 
of a USB stick which leaves all the drives for storage.

* Yes, you can add SSD for write (ZIL) or read (L2ARC) caching, but it's 
not required.

* ZFS is not overkill for a single spindle.  You can specify copies=2 so 
that each block is written in two separate locations, (yes, this cuts 
your available storage in half, just like mirroring) and if one of those 
copies gets corrupted (bit rot, whatever) the other one is still there. 
 Plus, all the checksumming that ZFS includes makes it quite a bit 
better than other filesystems for single spindle systems.

* There's no fsck that requires the filesystem to be unmounted - 
instead, ZFS scrubs can be done while the filesystem is online. (it's 
actually required to be online)

* I've done some rudimentary work with ZFS on Linux (ZOL) but nothing 
too advanced.  It works, but there are bits of functionality not 
available yet.  In terms of production use, I've heard rumors of folks 
using it in prod, but so far it's just rumors.


Thanks to the awesomeness that is ZFS, we're actually looking at the 
Solaris-based stuff (OmniOS, et al) for non-NAS use.  Folks who have 
worked with me before know my opinion of Solaris, and could tell you how 
impressive ZFS must be if I'm considering running Solaris. :D


cmh


On 6/17/13 3:03 PM, Adam Zion wrote:
> OK, so I've got my roll-your-own NAS up and running like so:
>
>   * Ancient Dell Dimension (headless after I got everything up and running)
>   * Crunchbang Linux (Debian-based)
>   * SAMBA
>   * 2 1 TB USB2 drives (amazingly, the ancient Dell has USB2 ports)
>   * SAMBA shares on one of the USBs
>   * Nighly rsync copies from one drive to the other to make a de facto
>     RAID 1
>
> Ain't pretty, and uses a lot more W of electricity than the Raspberry
> Pi-based NAS would have, but it works.
>
> My question is: would there be any advantage to using FreeNAS (or
> NAS4Free) on this device vs. remaining w/Crunchbang?



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