What's wrong with my system? Solaris not booting.

Booting the 32-bit OS ...

SunOS Release 5.7 Version Generic_106541-31 [UNIX(R) System V Release 4.0]
Copyright (c) 1983-2002, Sun Microsystems, Inc.
configuring network interfaces: le0.
Hostname: wz-ultra1
metainit: wz-ultra1: there are no existing databases

The system is coming up. Please wait.
checking ufs filesystems
/dev/rdsk/c0t0d0s7: I/O error
Can't open /dev/rdsk/c0t0d0s7
/dev/rdsk/c0t0d0s7: CAN'T CHECK FILE SYSTEM.
/dev/rdsk/c0t0d0s7: UNEXPECTED INCONSISTENCY; RUN fsck MANUALLY.

WARNING - Unable to repair one or more of the following filesystem(s):
/dev/rdsk/c0t0d0s7 /dev/rdsk/c0t1d0s5 /dev/rdsk/c0t0d0s1
Run fsck manually (fsck filesystem...).
Exit the shell when done to continue the boot process.

Type control-d to proceed with normal startup,
(or give root password for system maintenance):
single-user privilege assigned to /dev/console.
Entering System Maintenance Mode

Jul 14 11:32:19 su: 'su root' succeeded for root on /dev/console
Sun Microsystems Inc. SunOS 5.7 Generic October 1998
You have mail.
# df -k
Filesystem kbytes used avail capacity Mounted on
/proc 0 0 0 0% /proc
/dev/dsk/c0t0d0s0 480919 36770 396058 9% /
/dev/dsk/c0t1d0s6 1020255 519099 439941 55% /usr
fd 0 0 0 0% /dev/fd
/dev/dsk/c0t0d0s3 422967 305798 74873 81% /var
# more /etc/vfstab
#device device mount FS fsck mount mount
#to mount to fsck point type pass at boot options
#
#/dev/dsk/c1d0s2 /dev/rdsk/c1d0s2 /usr ufs 1 yes -
fd - /dev/fd fd - no -
/proc - /proc proc - no -
/dev/dsk/c0t0d0s4 - - swap - no -
/dev/dsk/c0t0d0s0 /dev/rdsk/c0t0d0s0 / ufs 1 no -
/dev/dsk/c0t1d0s6 /dev/rdsk/c0t1d0s6 /usr ufs 1 no -
/dev/dsk/c0t0d0s3 /dev/rdsk/c0t0d0s3 /var ufs 1 no -
/dev/dsk/c0t0d0s7 /dev/rdsk/c0t0d0s7 /export/home ufs 2 yes -
/dev/dsk/c0t1d0s5 /dev/rdsk/c0t1d0s5 /opt ufs 2 yes -
/dev/dsk/c0t0d0s1 /dev/rdsk/c0t0d0s1 /usr/openwin ufs 2 yes -
swap - /tmp tmpfs - yes -
# fsck /dev/rdsk/c0t0d0s7
Can't open /d...
:mad:

try doing a "devfsadm -Cv"
then retry the fsck.

If that doesn't work, post the startup screen from the format command by doing:
format < /dev/null

And post that.

Thanks Reborg all is working fine now.