[OpenIndiana-discuss] Problem/Question on mount lofs:

[Jim Klimov]

> On 26/06/2012 14:44, Armin Maier wrote:
>> Hello anybody!
>> I've got a problem centraly sharing ZFS filesystems.
>> What i want is to create zfs filesystems for different Usergroups and
>> i want to
>> share them in a central location.
>>
>> The idea was to create a "/mountbase" directory and share it with
>> "sharemgr"
>> (this is working and i can access the share from my Windows 7 machine
>> "\\openindiana\zfs$" )
>> Mount the zfs Filesystems do directories within the "/mountbase"
>> directory:
>>
>> mkdir /mountbase/zfsfilesys1
>> mount -F lofs /zfspool/zfsfilesys1 /mountbase/zfsfilesys1
>>
>> If i browse to the "/mountbase/zfsfilesys1" directory on the console i
>> can see
>> all the Contents and everything is fine, but when i open the share
>> "\\openindiana\zfs$" i do net see any directories. If i unmount the
>> "/mountbase/zfsfilesys1" Directory it appears on the Windows computer.
>> Does someone know why this happens? Is there a "smbserver" setting
>> which has to
>> be set? I do not use samba for sharing, i am using the Solaris smb
>> service
>> "svc:/network/smb/server:default".

AFAIK the Solaris kernel CIFS server, which is also used in OI,
does not allow sharing ZFS dataset hierarchies as a single
mountpoint (like you can do with NFS), and the CIFS clients
don't have a means to detect a nested mountpoint and call a
new mount operation for the nested datasets. I am not sure why,
maybe it is a protocol limitation, or a certain vendor's popular
client capability limitation.

SAMBA works around this problem by maintaining its own VFS layer
to map CIFS URLs to local filesystem IDs and inodes within these
filesystems (note that your nested datasets can have identical
inode numbers used to reference unrelated files stored within
these datasets). ZFS and Kernel CIFS/NFS servers don't do that -
they share each FS independently, and have no internal need for
such VFS mappings. That's what I've heard and read...

I might suggest that you do use SAMBA instead for this quest,
or that you try to set up a DFS (Distributed FileSystem) server
which actually serves mountpoint references - I heard rumors
that this can help combine several servers' CIFS shares into
something that looks like a single share for Windows clients.
A DFS server can be made as part of Windows Server for a long
time (Win2000 at least), and I think SAMBA can do that too.

HTH,
//Jim Klimov