Setting up ZFS - Filesystem Properties and Installing on Root

Mehmet Erol Sanliturk m.e.sanliturk at
Mon Nov 21 04:26:38 UTC 2011

On Sun, Nov 20, 2011 at 10:34 PM, APseudoUtopia <apseudoutopia at>wrote:

> Hello,
> I'll be setting up a server with ZFS on 9.0-RELEASE (when it's
> released...). I've never used ZFS before, and although I've been
> reading quite a bit about it, I have some questions.
> My plan is to use RAID-Z1 across 4 disks. I'll be using GPT, and I
> would like the root to be ZFS as well. I found a guide:
> In step #4, it has you create boot, swap, and zfs partitions on all 3
> (which would be 4 in my case) disks. Then, in step #5, you install the
> bootloader into all 3 (4) drives. Why do you need boot and swap
> partitions on EACH disk? It seems to me that you would only need disk
> 1 to have boot, swap, and zfs, and the other 3 disks only have one
> partition (using the entire drive) for zfs's pool. Does it have to do
> with the RAIDZ1 setup? Even then, I don't understand it because it's
> not disk mirroring, it's RAID. The BIOS is set to look on one specific
> disk for the loader, not all of them. It seems I'm not understanding
> something entirely here.

If disk 1 fails , the computer ( BIOS ) will look disk 2 .
If disk 2 fails , the computer ( BIOS ) will look disk 3 .

If disk ( n - 1 ) fails , the computer ( BIOS ) will look disk ( n ) .

> Also, with ZFS, you can have an unlimited number of filesystems,
> correct? I've been trying to figure out the best way to create these
> filesystems with the appropriate flags (specifically: atime,
> compression, devices, exec, quota, readonly, and setuid). If, for
> example, I set devices=off and suid=off on the tank/var filesystem, it
> is applied to the children filesystem, such as, /var/log, /var/db, and
> so on? The flags/properties can be changed on-the-fly, correct? If,
> for example, I set a filesystem noexec, but later realize I need exec,
> I can change it without issue?
> Does anyone with zfs experience have any tips on creating a filesystem
> layout, in terms of which filesystems to create and what
> flags/properties? Would it be bad to set noatime, nosuid, nodev, and
> noexec all on the tank, then allow each property appropriately for
> each directory as necessary? As in, set the whole tank noexec, but
> allow exec for /bin, /usr/home, /usr/local/bin, etc.?
> Thank you all very much!
> _______________________________________________

Thank you very much .

Mehmet Erol Sanliturk

More information about the freebsd-questions mailing list