Mount command doesn't work on Solaris System

Hi All,

I am using a solaris Sun-Fire-V440 server.
The OS is solaris.
My problem is whenever I run the command
mount | grep "^/ " | sed -e 's,^.*dsk/\([cd][0-9]*\).*$,\1,'
it should return a disk value as "d30" as it does on each of my other servers.But on this server I am not getting any o/p from this command.This causes my backup to fail everyday as I am using this command in a script to ensure FS backup on tape.
Moreover the o/p of "mount" command also doesn't provide any o/p.
Please help me with this as this is very critical.
Please find the o/p of some commands for your reference.

root@ecovs1a # uname -a
SunOS ecovs1a 5.10 Generic_141414-07 sun4u sparc SUNW,Sun-Fire-V440
root@ecovs1a #
root@ecovs1a # cat /etc/vfstab
#device         device          mount           FS      fsck    mount   mount
#to mount       to fsck         point           type    pass    at boot options
#
fd      -       /dev/fd fd      -       no      -
/proc   -       /proc   proc    -       no      -
/dev/md/dsk/d31 -       -       swap    -       no      -
/dev/md/dsk/d30 /dev/md/rdsk/d30        /       ufs     1       no      -
/devices        -       /devices        devfs   -       no      -
ctfs    -       /system/contract        ctfs    -       no      -
objfs   -       /system/object  objfs   -       no      -
swap    -       /tmp    tmpfs   -       yes     -
sharefs         -       /etc/dfs/sharetab       sharefs -       no      -
/dev/dsk/c5t600C0FF0000000000980BD31E3115E00d0s6 /dev/rdsk/c5t600C0FF0000000000980BD31E3115E00d0s6 /var/oracle/backup ufs 1 no rw,logging
root@ecovs1a #
root@ecovs1a # df -hk
Filesystem             size   used  avail capacity  Mounted on
/dev/md/dsk/d30         63G    38G    25G    61%    /
/devices                 0K     0K     0K     0%    /devices
ctfs                     0K     0K     0K     0%    /system/contract
proc                     0K     0K     0K     0%    /proc
mnttab                   0K     0K     0K     0%    /etc/mnttab
swap                   4.8G   1.5M   4.8G     1%    /etc/svc/volatile
objfs                    0K     0K     0K     0%    /system/object
sharefs                  0K     0K     0K     0%    /etc/dfs/sharetab
/platform/sun4u-us3/lib/libc_psr/libc_psr_hwcap1.so.1
                        63G    38G    25G    61%    /platform/sun4u-us3/lib/libc_psr.so.1
/platform/sun4u-us3/lib/sparcv9/libc_psr/libc_psr_hwcap1.so.1
                        63G    38G    25G    61%    /platform/sun4u-us3/lib/sparcv9/libc_psr.so.1
fd                       0K     0K     0K     0%    /dev/fd
swap                   4.8G   1.4M   4.8G     1%    /tmp
swap                   4.8G    48K   4.8G     1%    /var/run
root@ecovs1a #
root@ecovs1a # mt stat
HP DAT-72 tape drive:
   sense key(0x0)= No Additional Sense   residual= 0   retries= 0
   file no= 0   block no= 0
root@ecovs1a #
root@ecovs1a # mount
root@ecovs1a # mount -h
root@ecovs1a #

Please feel free to ask any other command o/p if needed.

What does this say:

which mount
file `which mount`
ls -l `which mount`

thanks for ur concern dude..But I got an answer to my problem ...I found that the mount file located in /usr/sbin/../../mount was of zero bytes..Hence my system was not able to get the required output..When I replaced the mount configuration file from some other node..my command worked!!!...Thanks once again

Since the issue has been fixed and the solution to my problem has also been provided., I would request the moderator to mark this thread as solved and close it..Thanks