you should first consider why / is running out of space. - run bdf to list all filesystems - run du -sk on each directory of / which isn't a filesystem (from bdf output)
An alternative to extend this filesystem may be to move some of those directories from / to another filesystem: link them to new location.
"/" filesyste should be well "confined", no new files should go directly into it, except the root history file updates, cde preferences files, mozilla files, etc. This make "/" pretty "static".
Run this command to see which are the largest and newest file you have in "/" alone.
du -ks $(find / -type f -mtime -30 -xdev) | sort -n
This can help you identify why you are going low on space.
There's also an other way to extend root filesystem that is quite complex.
Supposing a 2 internal disks configuration, all vg00 LVs mirrored.
1) fsadm on /tmp (and lvreduce /tmp) as many MBs as you need for root fs; 2) extend root logical volume and extend its filesystem; 3) extend back to the desired value /tmp
This is due to "/" filesystem being in contiguos and strict allocation policy.
I suspect you've either got a process writing to root that would be better writing to a filesystem of its own or a backup writing to a non-existent device. This is quite common: what happens is a typo in the device name when you run a backup command resulting in a large file in the /dev/rmt directory. Check this before taking the drastic (and usually unnecessary) action of increasing /.
Mark Syder (like the drink but spelt different)
The triumph of evil requires only that good men do nothing
I have a possible solution for you but it utilizes some advanced LVM commands and requires you to really understand your disk layout. Do not try this without fully understanding this and thinking it through.
Lets assume you have 2 disks in vg00 one with the boot area and the / filesystem and the other with other filesystems but with sufficient room.
On your boot disk /dev/dsk/c1t15d0 you have
lvol1 lvol2 lvol3 lvol4 lvol5
Lvol3 cannot be extended since / needs to be contiguous and lvol4 is in the way.
if you have 2 disks in vg00 examples /dev/dsk/c1t15d0 and /dev/dsk/c2t15d0 and the 2nd disk has some room.
this will move lvol4 to the other disk providing a hole for the / filesystem.
Then you can do the following lvextend -L 200 /dev/vg00/lvol3 (assuming you have that space) fsadm -F vxfs -b 200M / (to extend the filesystem.. This assumes onlinejfs)
Then you can move lvol4 back to the disk.. pvmove -n /dev/vg00/lvol4 /dev/dsk/c3t15d0 /dev/dsk/c1t15d0
