I've got a NW 6.5 SP4a server which was working OK with 2 GB RAM until I
recently upped it to 4 GB. I found that the "auto tune" mechanism now cuts
in and limits the file cache size to 1 GB RAM, which was not what I put the
extra 2 GB in for. The server is doing mainly F&P with some ZfW NLMs
running, along with Sophos (real-time check inactive) and BE 9.1 for backups.
I ran Hamish's MEMCALC.NLM and accepted its changes, rebooted the server.
That set the upper file cache limit to 2.4 GB, much better. However, now I
get these messages when the backup runs:

28-11-2006 10:38:30 pm: SERVER-5.70-3729
Severity = 0 Locus = 17 Class = 21
Server logical address space is running low. Increase the available
logical space by setting File Cache Maximum Size to 2016894976.
28-11-2006 11:03:14 pm: SERVER-5.70-3729
Severity = 0 Locus = 17 Class = 21
Server logical address space is running low. Increase the available
logical space by setting File Cache Maximum Size to 1881261056.
28-11-2006 11:25:50 pm: SERVER-5.70-3729
Severity = 0 Locus = 17 Class = 21
Server logical address space is running low. Increase the available
logical space by setting File Cache Maximum Size to 1948369920.
28-11-2006 11:27:02 pm: SERVER-5.70-3729
Severity = 0 Locus = 17 Class = 21
Server logical address space is running low. Increase the available
logical space by setting File Cache Maximum Size to 1948369920.
29-11-2006 12:10:39 am: SERVER-5.70-3729
Severity = 0 Locus = 17 Class = 21
Server logical address space is running low. Increase the available
logical space by setting File Cache Maximum Size to 1947386880.

Should I just down the cache limit to the recommended lower value, or is
there more I need to do? I have a hazy understanding of 6.5 memory
management, and the messages mean little to me. As far as I can see, Remote
Manager reckons the server's fine. The server was running at 800-900 MB
file cache RAM with 2 GB of memory, so I stupidly assumed that with 4 GB of
RAM it would use at least 2.5 GB of RAM for file caching. Does anyone
(Hamish?) know what's going on? Thanks for any help or suggestions...