During a boot, the /etc/rcS script runs the fsck(1M) command to check the integrity of file systems marked "fsck" in /etc/vfstab. If fsck(1M) cannot repair a file system automatically, it interrupts the boot procedure and produces this message. When fsck(1M) gets into this state, it cannot repair a file system without losing one or more files, so it wants to defer this responsibility to you, the administrator. Data corruption has probably already occurred.
First run fsck -n on the file system, to see how many and what type of problems exist. Then run fsck(1M) again to repair the file system. If you have a recent backup of the file system, you can generally answer "y" to all the fsck(1M) questions. It is a good idea to keep a record of all problematic files and inode numbers for later reference. To run fsck(1M) yourself, specify options as recommended by the boot script. For example:
# fsck /dev/rdsk/c0t4d0s0
If you do not have a backup, ask an expert to run fsck(1M) for you.
For more information on file checking, see the section on checking file system integrity in the System Administration Guide, Volume 1.