AWE on 4GB multi-instance box?

Hi
We have a SQL server 2000 cluster, built on Windows 2000 Advanced server.
We are using an Active / Passive configuration which has 4 instances of SQL
Enterprise, and 1 Instance of IIS.
Both boxes are identical, and clustering works just fine.
However, in order to use the 4Gb in each box, should we enable the /3Gb
switch in Boot.Ini?
How then do we configure each instance of SQL Server? I believe that once
the /3Gb switch is enabled, that SQL will grab all the memory for itself,
leaving only 128Mb for the OS. We would probably need to specify a maximum
memory usage requirement, per instance, if that was to be the case.
There seems to be 2 options to me. Can anyone offer advice on whether we
should take:
1). Disable the AWE, via the removal of the /3Gb switch, and let SQL Server
manage its own memory
2). Enable AWE, via the use of the /3Gb switch, but then specify the maximum
memory each instance of SQL Server can use.
Does anyone have a view?
Thanks
Paul Aspinall
MCSD, MCDBA
Paul,
The /3GB switch does not enable or disable AWE. That is done via the AWE
option of sp_configure. If you have 4 actual instances of SQL Server plus
IIS on a single box with only 4GB of memory you certainly do not want to use
/3GB. You must share that 4GB with all 5 instances plus the OS and do not
want anything to swap to the swap file. Is there a particular reason to
have 4 separate instances vs. one with all the db's in it? It's hard to say
what the proper memory config should be given I know nothing about any of
your instances or how they are used. You might simply want to stay with
dynamic memory config on all 4 with no /3GB. AWE is only really useful with
more than 4GB anyway. It's IIS that I would be most worried about since it
doesn't play as well with others as SQL Server does.
Andrew J. Kelly SQL MVP
"Paul Aspinall" <paul@.aspy.co.uk> wrote in message
news:oG4Be.28164$O22.20831@.fe1.news.blueyonder.co. uk...
> Hi
> We have a SQL server 2000 cluster, built on Windows 2000 Advanced server.
> We are using an Active / Passive configuration which has 4 instances of
> SQL Enterprise, and 1 Instance of IIS.
> Both boxes are identical, and clustering works just fine.
> However, in order to use the 4Gb in each box, should we enable the /3Gb
> switch in Boot.Ini?
> How then do we configure each instance of SQL Server? I believe that once
> the /3Gb switch is enabled, that SQL will grab all the memory for itself,
> leaving only 128Mb for the OS. We would probably need to specify a maximum
> memory usage requirement, per instance, if that was to be the case.
> There seems to be 2 options to me. Can anyone offer advice on whether we
> should take:
> 1). Disable the AWE, via the removal of the /3Gb switch, and let SQL
> Server manage its own memory
> 2). Enable AWE, via the use of the /3Gb switch, but then specify the
> maximum memory each instance of SQL Server can use.
>
> Does anyone have a view?
> Thanks
>
> Paul Aspinall
> MCSD, MCDBA
>