1. do fsck -ofull (no space in ofull) of that partition e.g. /dev/u1. plse note all this preferably to be done in single user mode (-ofull for HTFS/VXFS or -s for EAFS.
2. if it gives error at phase 5 then possibly your log files in HTFS file systems are corrupt. if so then read from clause 9
3. if fsck at pt 1 fails early then try fsck -y on <fiesystem>
4. if this suceeds then try read only mount.
mount -r /dev/u1 /u1 (example. susbtitute yr file system)
5. if fsck -y succeds but mount -r fails, then try fsck -y again. but this time mount on diff file directory,
mount -r /dev/u1 /mnt.
6. if mount -r succeds then chnage in yr /etc/default/filesys.
substitute ur original mountdir with the new one. in or case /u1 would be changed for /u1 to /mnt
7. then try mount -o remount /mnt - (the mountdir name). before this ensure that yr current mountdir and mountdir name if /etc/default/filesys are same.
8. if it succeds then umount /mnt, restore your origingal /etc/default/filesys i.e. change back yr original mountdir and try mountall
9. if fsck -ofull fails at phase 5 then yoy would have to truncate yr HTFS journal log file. to slove this read TA no 113821 from SCO. (search SCO for corrupted or power)