I wrote a Perl script that will compact unused space on subdisks. In our environment, as different volumes grow, they can be moved to different disks, or they can be deleted. This can result in holes of usable space on the disks or it can result in split subdisks during a grow.

This Perl script will join adjacent or split subdisks, and compact regions of empty space from the disks. Right now there are only 3 options.

• -n print what would be done instead of doing it.
• -c don't bother aligning the subdisks on cylinder boundaries, just pack them as tight as you can. (typical cylinder boundaries are 1520 for 2GB disks and 2160 for 4GB disks (sectors))
• -d print out debugging information

If it encounters a non redundant volume (simple volume or stripe) it will exit and say so.

For logdisks (specifically RAID-5), it uses my personal preference, which is to put all logdisks at the end of the VM disk.

Available at ftp.eng.auburn.edu:pub/doug/vxpack.tcl