From: dseeman@novell.com (Daniel Seeman)
Subject: Re: Adding volumes to server
Organization: Novell Inc., San Jose, Califonia
Date: Mon, 21 Dec 1992 19:25:44 GMT

In article <todd.strauch-211292062857@no-name-medadmin.med.umich.edu> todd.strauch@med.umich.edu (Todd R Strauch) writes:
>In article <1h1aobINN4lo@news.cerf.net>, raymond@nic.cerf.net (Raymond
>Roque) wrote:
>> 
>> To Sys Admins and Novell Certified Engineers:
>> 
>> I'm trying to add an external hard disk to our Novell server, 
>> a 386 version 3.11 for the MacIntosh (20 users).
>> 
>> The server is a first generation 386 which only upgrades to
>> 6 Megs of RAM memory, an ALR 220.
>> 
>> Currently, three volumes are mounted totaling 600Megs of
>> hard disk space. Viewing their options from the install
>> loadable module, each volumes were configured using 16K blocks.	
>> 
>> After creating another volume for this hard disk (1300megs),
>> I tried to mount it in the install NLM. The server gave me
>> an error of: "Cache memory allocator error out of available memory"
>> 
>> To mount a total of 1900Meg in the server, how much RAM memory
>> do I need for the server?
>> 
>> Confering with other people and the installation manuals (taking
>> into consideration that we are using a MacIntosh environment),
>> the computation should be (Page 113-114 of the installation
>> manual):
>> 
>> (.032 * (Total hard disk space)) / block size = RAM memory required
>> 
>> 0.032 for name space support since it is a Mac environment.
>> 
>> If the block size is 16K which was used with the other
>> volumes, I get 3.8Megs for the RAM requirement. This seems to
>> be inaccurate because at 6 Megs of RAM, my server flags the 
>> error.
>> 
>> If the block size is 4K which is the standard configuration, 
>> I get 15.2 (approx 16 Megs) for the RAM requirement.
>> 
>> Can anyone help?
>> 
>> I just need more info before deciding to get a new motherboard
>> for the server.
>> 
>You are correct in that a 1900Mb volume supporting the Mac name space will
>consume 3.8Mb, but you also have to add at least 2Mb for the operating
>system as well as memory to handle NICs and connections to the server and
>any other additional NLMs that may be loaded but are necessary for the
>operation of the server (INSTALL, MONITOR, ATCON, etc...).  This will
>easily push you to the limit on your 6Mb.  Be aware that Novell stresses
>that their memory calculations are MINIMUM memory requirements.  In most
>situations, you will probably exceed them (somewhat).
>
Hi,

Todd is correct except for one point.  Actually you should add a minimum of 4Mb
to your calculation.  This more accurately represents the minimum memory amount 
needed to load the server.  So, your calculation of 3.8 meg should probably have
the 4Mb added to it to make a total of 7.8 meg.  This may be a bit more consis-
tant with the results the original user saw (i.e. running out of memory with on
ly 6meg installed).

One last thing I should add is that the equations we used to come up with these
numbers were determined statistically (notice the equation is just a straight
line) and were probably made with data taken from relatively small volumes.  You
will find some pretty absurd answers when larger volume values are input to
the equation.  Apparently the memory usage becomes non-linear for large volumes.
By the way, I am defining "large volumes" as ones over about 1 or 2 gigs.

I hope this information helps...

Think Peace and Happy Holidays!

Dan Seeman
Novell
Walnut Creek,Ca.