zfs code - Nov 2007 - cannot mount ''mypool'': Input/output error

Hello, 

I have a question about using ZFS with Fuse.  A little bit of background of what
we''ve been doing first...  We recently had an issue with a Solaris
server where the permissions of the main system files in /etc and such were
changed.  On server restart, Solaris threw an error and it was not possible to
log in, even as root.

So, given that it''s the only Solaris machine we have, we took out the
drive and after much trouble trying with different machines, we connected it to
Linux 2005 Limited Edition server using a USB to SATA connector.  The linux
machine now sees the device in /dev/sda* and I can confirm this by doing the
following:

[root]# fdisk sda 

Command (m for help): p 

Disk sda (Sun disk label): 16 heads, 149 sectors, 65533 cylinders 
Units = cylinders of 2384 * 512 bytes 

Device Flag    Start       End    Blocks   Id  System 
sda1          1719     11169  11264400    2  SunOS root 
sda2  u          0      1719   2049048    3  SunOS swap 
sda3             0     65533  78115336    5  Whole disk 
sda5         16324     65533  58657128    8  SunOS home 
sda6         11169     16324   6144760    7  SunOS var 

Given that Solaris uses ZFS, we figured to be able to change the permissions,
we''ll need to be able to mount the device.  So, we found Fuse,
downloaded, installed it along with ZFS.  Everything went as expected until the
creation of the pool for some reason.  We''re interested in either sda1,
sda3 or sda5, we''ll know better once we can mount them...

So, we do ./run.sh & and then the zpool and zfs commands are available.  My
ZFS questions come here, once we run the create command, I get the error
directly:

[root]# zpool create mypool sda 
fuse: mount failed: Invalid argument 
cannot mount ''mypool'': Input/output error 

However, if I list the pools, clearly it''s been created: 

[root]# zpool list 
NAME                    SIZE    USED   AVAIL    CAP  HEALTH     ALTROOT 
mypool                 74.5G     88K   74.5G     0%  ONLINE     - 

It seems the issue is with the mounting, and I can''t understand why: 

[root]# zfs mount mypool 
fuse: mount failed: Invalid argument 
cannot mount ''mypool'': Input/output error 

[root]# zfs mount 

I had searched through the source code trying to figure out what argument was
considered invalid and found the following:

    477     if (res == -1) {
   478         /*
   479          * Maybe kernel doesn''t support unprivileged mounts, in
this
   480          * case try falling back to fusermount
   481          */
   482         if (errno == EPERM) {
   483             res = -2;
   484         } else {
   485             int errno_save = errno;
   486             if (mo->blkdev && errno == ENODEV &&
!fuse_mnt_check_fuseblk())
   487                 fprintf(stderr, "fuse: ''fuseblk''
support missing\n");
   488             else
   489                 fprintf(stderr, "fuse: mount failed: %s\n",
   490                         strerror(errno_save));
   491         }
   492 
   493         goto out_close;
   494     }

in the following file: 

http://cvs.opensolaris.org/source/xref/fuse/libfuse/mount.c 

I didn''t really understand what that was suggesting the issue was,
other than the comment saying "unprivileged mounts"... I looked on
http://docs.sun.com/app/docs/doc/819-2240/zfs-1m and found a command:

zfs allow [-ldug] "everyone" |user |group [,,....] 
-[uge] "everyone" |user |group [,,....] 
Specifies to whom the permissions are delegated. Multiple entities can be
specified as a comma-separated list. If none of the -uge options are specified,
then the argument is interpreted preferentially as the keyword ?everyone?, then
as a user name, and lastly as a group name. To specify a user or group named
everyone?, use the -u or -g options. To specify a group with the same name as a
user, use the -g options.

However, when I tried it, it was not recognized: 

[root]# zfs allow 
unrecognized command ''allow'' 

Any thoughts or suggestions would be much appreciated! 

Thank you very much
--
This messages posted from opensolaris.org

Hi Nabeel,

Nabeel Saad wrote:
> So, we do ./run.sh & and then the zpool and zfs commands are available.
My ZFS questions come here, once we run the create command, I get the error
directly:
> 
> [root]# zpool create mypool sda 
> fuse: mount failed: Invalid argument 
> cannot mount ''mypool'': Input/output error 
Are you sure this is what you wanted to do?

If you already had a pool in sda and you create another one in the same 
device, you will overwrite the old pool and you no longer will be able 
to access the data you had in there...

Perhaps you wanted to do "zpool import" instead?
> It seems the issue is with the mounting, and I can''t understand
why:
> 
> [root]# zfs mount mypool 
> fuse: mount failed: Invalid argument 
> cannot mount ''mypool'': Input/output error 
Before mounting the first zfs-fuse filesystem, you have to do "modprobe 
fuse".
> [root]# zfs allow 
> unrecognized command ''allow'' 
This functionality is not available in the latest zfs-fuse version.
> Any thoughts or suggestions would be much appreciated! 
One suggestion: this mailing list is more appropriate for discussing the 
ZFS code. If you have questions regarding zfs-fuse, please use the more 
appropriate discussion group here:

http://groups.google.com/group/zfs-fuse/about

Thanks,
Ricardo

--
   <http://www.sun.com>  	* Ricardo Manuel Correia *

Lustre Engineering Group
*Sun Microsystems, Inc.*
Portugal

Ricardo.M.Correia at Sun.COM