zfs discuss - Nov 2005 - Re: [osol-discuss] Re: Re: OpenSolaris - Why should I care?

On Tue, Nov 29, 2005 at 04:37:56PM +0100, Joerg Schilling
wrote:
> Darren J Moffat <Darren.Moffat at Sun.COM> wrote:
> 
> Maybe I did not  yet grok them, could you help me please?
> 
> I tried ''zfs set mountpoint=legacy'', but while mount -F
zfs pool /mnt
> works, mount -F zfs /dev/lofi/1 /mnt does not work and gives this message:
> 
> 	cannot open ''/dev/lofi/1'': invalid filesystem name
> 
> If I like to mount a zfs partition, I will need to do this when / is
mounted
> read only and /dev/ is empty. So after some checks, I willl e.g. know that
> the device that holds the zfs I like to mount is e.g. on:
> 
> /devices/pci at 0,0/pci-ide at 7,1/ide at 1/sd at 1,0:d
> 
> How do I tell this zfs to be able to mount it?
The above invocation doesn''t make any sense.  ZFS filesystems are not
associated with a single device, therefore it cannot possibly take a
device name as a mount source.  Yes, if you happened to have a single
disk pool you could theoretically do this, but it''s an edge case and
ZFS
has better systems to deal with this.

You will need to import the pool from the device first.  But why have
legacy mounts at all?  This is what alternate root pools were designed
for.  You can do:

	# zpool import -d /dev/lofi -R /mnt <pool>

Which will interpret all your pool mounts in context of
''/mnt''.  Again,
if you really want to use legacy mounts you can do so, but you must
import the pool first.

Note that importing a pool requries writing to /etc/zfs/zpool.cache, but
using an alternate root does not.  There is an open RFE for a temporary
(-t) option that does the same thing as "-R /" but without the
explicit
alternate root.

Please send all further responses to zfs-discuss.

- Eric

--
Eric Schrock, Solaris Kernel Development       http://blogs.sun.com/eschrock

On 11/29/05, Eric Schrock <eric.schrock at sun.com>
wrote:
> On Tue, Nov 29, 2005 at 04:37:56PM +0100, Joerg Schilling wrote:
> > Darren J Moffat <Darren.Moffat at Sun.COM> wrote:
> >
> > How do I tell this zfs to be able to mount it?
>
> The above invocation doesn''t make any sense.  ZFS filesystems are
not
> associated with a single device, therefore it cannot possibly take a
> device name as a mount source.
oh ...

# /sbin/zpool create -m /export/Blastware -f OpenSolaris c1t1d0

# /sbin/zpool list
NAME                    SIZE    USED   AVAIL    CAP  HEALTH     ALTROOT
OpenSolaris            68.0G   58.0K   68.0G     0%  ONLINE     -

Single devices is all I have been doing.  Guess I better get with the program.

On Tue, Nov 29, 2005 at 11:51:17AM -0500, Dennis Clarke
wrote:
> 
> oh ...
> 
> # /sbin/zpool create -m /export/Blastware -f OpenSolaris c1t1d0
> 
> # /sbin/zpool list
> NAME                    SIZE    USED   AVAIL    CAP  HEALTH     ALTROOT
> OpenSolaris            68.0G   58.0K   68.0G     0%  ONLINE     -
> 
> Single devices is all I have been doing.  Guess I better get with the
program.
Well, it''s _possible_ to have a single device in a pool, and have no
filesystems other than the root filesystem, but it''s not exactly the
ZFS
design center ;-)

As soon as you type ''zfs create'', you no longer have a
one-to-one
relationship between devices and filesystems.

- Eric


--
Eric Schrock, Solaris Kernel Development       http://blogs.sun.com/eschrock