ZFS snapshot restore not quite working; missing steps?

[Steven Hartland]

----- Original Message ----- 
From: "Jeff Chan" <jeffc at supranet.net>
To: <freebsd-fs at freebsd.org>
Sent: Sunday, May 18, 2014 11:53 AM
Subject: Re: ZFS snapshot restore not quite working; missing steps?


> On Sunday, May 18, 2014, 3:25:39 AM, Steven Hartland wrote:
>> Not used legacy here have you tried:
>> zfs set mountpoint=/ zroot
> 
> It was tried initially.  Trying again a second time
> 
> zfs set mountpoint=legacy zroot
> 
> was tried.
> 
>> Silly question given your using mfi have confirmed your controller /
>> machine bios are set to boot from the relavent disk?
> 
> Not silly; yes it does boot from the right disk.
> 
>> Also have you confirmed zfs in /boot/loader.conf e.g.
>> zfs_load="YES"
>> vfs.root.mountfrom="zfs:zroot"
> 
> Yes.
> 
>> Finally do be aware its not ideal to use a RAID controller for ZFS
>> your better of with a HBA which does less "fancy" stuff when
>> communicating with the disks allowing ZFS do see whats really going
>> on.
> 
> Yes, indeed.  It's an LSI 2208 which doesn't seem to be reflashable
> into HBA like a LSI 2008, so we're running each of the three disks as
> a separate RAID-0, with RAID hardware read and write caching turned
> off (as it supposedly works faster with ZFS that way).   Would have
> preferred HBA, but we're trying to do the best with the hardware we
> have. 

Yer here you there; we've had to do the same, this is layout we use which
Is that configured by mfsbsd (http://mfsbsd.vx.sk/):

zroot                           22.8G  55.5G   144K  none
zroot/root                      20.8G  55.5G  19.4G  /
zroot/root/tmp                   592K  55.5G   592K  /tmp
zroot/root/var                  1.39G  55.5G  1.39G  /var
zroot/swap                       266M  57.2G   266M  -

Pool layout:-
zpool status zroot
  pool: zroot
 state: ONLINE
  scan: none requested
config:

        NAME                                            STATE     READ WRITE CKSUM
        zroot                                           ONLINE       0     0     0
          mirror-0                                      ONLINE       0     0     0
            gptid/d27aba97-5c20-11e2-a017-00259088112a  ONLINE       0     0     0
            gptid/d3226aa9-5c20-11e2-a017-00259088112a  ONLINE       0     0     0

errors: No known data errors

> We wonder if things like the MBR and zfs boot loader are happy.  How
> does one review whether those are set up correctly?

Not had any issues here

As a test I would a micro install using mfsbsd, only takes a few mins which will
ensure the basic layout is all good and the machine boots.

If all good you can then boot back to the install, restore from you backup and
reboot.

    Regards
    Steve