Installing FreeNAS To A USB Thumbdrive

[HoneyBadger]

You know, sometimes I wish someone would send me a box with old Xeons and 32GB of RAM just so I could test how much a system that old "can" handle FreeNAS.

As someone who uses an "old Xeon" for his main home NAS, I take offense to that my good sir.

/adjusts monocle

But I might be able to get a dual-X5450 32GB machine up to bash on for giggles.

 

[Arvo Bowen]

What would be the drawback of having 7 of my drives (2TB) in a RAIDZ2. FreeNAS does not like the 7 drives, it wants 6. But when it says optimal does that mean it will perform slower with 7 drives?

 

[HoneyBadger]

What would be the drawback of having 7 of my drives (2TB) in a RAIDZ2. FreeNAS does not like the 7 drives, it wants 6. But when it says optimal does that mean it will perform slower with 7 drives?

Hi Arvo,

Short answer: Yes, a 7-drive RAIDZ2 will probably be slower than the 6-drive RAIDZ2.

Computers really like the number two, powers of two, and things that are divisible nicely by twos and powers of two. So it likes 6 disks because it has 4 drives worth of data (2^2) and 2 of parity.

Let's say you write a 128KB stripe of data to that array. We'll ignore the parity drives for now; with four drives holding data, it divides very nicely into four chunks of 32KB, which go to each disk. And if you're using 4KB-sector drives, each chunk takes up eight sectors. Nice round numbers.

But if you have a 7-drive RAIDZ2, you're going to have five data disks. 128KB/5 = 25.6KB per drive. Uh oh, that didn't divide nicely. You're now writing 6 full sectors (24KB) and one partial sector (1.6KB) to each disk.

With all that said

If you're only connecting over a single gigabit link, you'll probably be able to saturate the link with either configuration. But the 6-drive RAIDZ2 is the "recommended setup"

 

[Arvo Bowen]

Wow, thanks HoneyBadger!!! That was perfectly explained and helped out a bunch. I will be going with the 7 drive RAIDZ2 with 1 hot spare.

Now I just need to worry about the access rights... FreeNAS is a little different than my old Win box when it comes to permissions...

 

[gpsguy]

Hot spares don't work in FreeNAS (yet).


Sent from my phone

 

[Arvo Bowen]

Hot spares don't work in FreeNAS (yet).


Sent from my phone

Then why is there a setting for it? Looking under volume status I see my drive as a spare... :)

 

[gpsguy]

Read the thread "why hot spare doesn't work". I can't link to it from my phone. Just search the forum for it.


Sent from my phone

 

[HoneyBadger]

It's there for future hot-spare functionality that's been promised for FreeBSD (which FreeNAS is based on) but it doesn't exist as of yet. They're still promising it for FreeBSD 10.0, but I'm not holding my breath.

As of now you can have it there, unassigned, and manually offline/replace the bad disk if failure strikes, or keep it offline and unpowered to reduce the power-on-hours.

 

[cyberjock]

Actually.. it's promised in 10.1 last I heard. But it was promised in 8,3 then 9.0, then 9.1, and then 9.2. So don't hold your breath waiting.

 

[HoneyBadger]

Considering that Solaris still has the odd issue with ZFS hotspares, I'm unsurprised that there's issues with implementing it.

But for OP's purposes I would just suggest keeping the seventh disk offline, unplugged, and wait to replace if needed.

Or add five more and make a 12-drive two-vdev RAIDZ2 monster pool. ;)

 

[Arvo Bowen]

Thanks everyone! Cold spare (check)

 

[Arvo Bowen]

Well, FreeNAS seems stable with my current config. Everything is looking great except these freaking permission issues! I have been trying to get this to work for days now with no luck...

1) I have a domain, setup a group for admins called 'domain admins', add a user named 'arvo' to the group via my DC.
2) I created a group called 'xbmc_r' then added a user called 'media' to it.
2) I set up my storage dataset called 'xbmc', Click on the change permissions button, owner(user)=nobody, owner(group)=domain admins, type of ACL=Windows via freenas...
3) I set up a share called 'xbmc' via freenas.
4) I then log in windows with user 'arvo' and I can access the shared folder called 'xbmc' with full access. I then set the permissions to add group 'xbmc_r' with read access via windows acl.
5) I then log in windows with user 'media' and can NOT access the folder 'xbmc'.

It's like I'm only able to access the folder using log in 'arvo' because of the 'domain admins' group. In freeNAS even though I have type of ACL = windows I don't think it actually uses the windows ACLs!!!

Ideas?

 

[Arvo Bowen]

Ended up opening a new thread because this one started out about something else and is in fact close/solved. ;)

New thread: http://forums.freenas.org/index.php?threads/windows-permissions-on-a-domain.20282/

 

[KempelofDoom]

You know, sometimes I wish someone would send me a box with old a** Xeons and 32GB of RAM just so I could test how much a system that old "can" handle FreeNAS.

Wish I had read that earlier. I might still be able to get you that level of hardware. A company I used to work for still rocks Dell 2680's for production and they just replaced most of that with a virtualized FreeNAS on top of a Synology NAS. I'll see if I can get them to hold off on tossing it.

 

[cyberjock]

That would be amazing if you could do that. :)