Question : NetWare 6 Server volume SYS out of disk space (15.9 GB free, Monitor shows 15.9 TB free)

NetWare 6 SP5 (small business suite)
GroupWise 6 SP2
single server, single volume SYS

Windows Explorer (logged in as Admin) shows 15.9 TB available, although the last accurate measurement was 15.9 GB (this is not a typo).  Right clicking on the volume (in Explorer) shows a garbled amount of free space, but does show the actual size of the drive.
NetWare Monitor screen showns volume SYS using 149% of available space
Repeating volume SYS out of disk space error
Originally thought this was a GroupWise error, but now appears to be something else.

Is this a corruption issue with the volume?

We noticed a GroupWise problem with the MTA a few days ago (see my GroupWise question for more details), then started getting a "Volume ... SYS out of disk space" error, followed by a message saying "There are no deleted files using disk space."  At the time, we had 15.9 GB of space available of approximately 72 GB total space.

We deleted a 9+ GB archive copy of our database when the out of disk space message appeared, then purged all deleted files, and the GroupWise started working... but later the problem appeared again, and now the out of space error continues even when we run a purge (of deleted files) of the entire SYS volume.

The server appears to be working fine, files can be saved, changed, etc.  We can create a new directory on the SYS volume, copy files successfully, etc.  This appears to be a space reporting issue, but we do not want to lose data.  Any ideas?

Answer : NetWare 6 Server volume SYS out of disk space (15.9 GB free, Monitor shows 15.9 TB free)

I once had a similar problem and had to rebuild the pool.  Hopefully you have a good backup.  When I ran the pool rebuild, I did not lose any data, but it is very possible that you can lose data.  Here are the steps to rebuild a pool:

1.  NSS /POOLREBUILD
2.  Select the pool that contains the damaged volume, then press enter.
3.  Reactivate/mount the Volume

If you have a traditional volume(non-NSS), you would need to use vrepair.