Is anybody out there pushing the memory limits ( for shared memory )
with DB2 version 8 on LINUX. The Advanced Admin IBM Press Book
claims that kernel 2.4 can only grab 1.75 GB. We have just gotten
RedHat Enterprise Linux AS release 3 ( kernel 2.4.21-9.0.1.ELcustom)
and just by trying sizes, it looks like it can address an eyelash
smaller than 4 GB. I don't know if I should trust it for production
use. Does anybody have experience with that? I just don't trust it
yet.

Matt

With SuSE SLES 8 service pack 2 and DB2 v8.1 FixPak 2 or later, extra
memory can be used for bufferpools for a maximum of about 2.2GB.

If you want to use more memory, buy a 64-bit AMD or Intel chip - DB2
Linux supports 64-bit memory addressabiltiy on both of those platforms.

Matthew Dauphinee wrote:

> Is anybody out there pushing the memory limits ( for shared memory )
> with DB2 version 8 on LINUX. The Advanced Admin IBM Press Book
> claims that kernel 2.4 can only grab 1.75 GB. We have just gotten
> RedHat Enterprise Linux AS release 3 ( kernel 2.4.21-9.0.1.ELcustom)
> and just by trying sizes, it looks like it can address an eyelash
> smaller than 4 GB. I don't know if I should trust it for production
> use. Does anybody have experience with that? I just don't trust it
> yet.
>
> Matt

Blair,

That makes complete sense to me, but our management isn't very
interested in 64 bit computing yet. Painful.

Well if anyone else is seeing upwards of 3.5GB bufferpools on 32 bit
Intel machines running LINUX, I'd like to hear about it.

Matt


Blair Adamache <badamache@nospamtodaysiryahoo.com> wrote in message news:<40735022.504595E0@nospamtodaysiryahoo.com>.. .
> With SuSE SLES 8 service pack 2 and DB2 v8.1 FixPak 2 or later, extra
> memory can be used for bufferpools for a maximum of about 2.2GB.
>
> If you want to use more memory, buy a 64-bit AMD or Intel chip - DB2
> Linux supports 64-bit memory addressabiltiy on both of those platforms.
>
> Matthew Dauphinee wrote:
>
> > Is anybody out there pushing the memory limits ( for shared memory )
> > with DB2 version 8 on LINUX. The Advanced Admin IBM Press Book
> > claims that kernel 2.4 can only grab 1.75 GB. We have just gotten
> > RedHat Enterprise Linux AS release 3 ( kernel 2.4.21-9.0.1.ELcustom)
> > and just by trying sizes, it looks like it can address an eyelash
> > smaller than 4 GB. I don't know if I should trust it for production
> > use. Does anybody have experience with that? I just don't trust it
> > yet.
> >
> > Matt

"Matthew Dauphinee" <mdauphinee@performics.com> wrote in message
news:41acab23.0404070727.3cbd9aab@posting.google.c om...
> Blair,
>
> That makes complete sense to me, but our management isn't very
> interested in 64 bit computing yet. Painful.
>
> Well if anyone else is seeing upwards of 3.5GB bufferpools on 32 bit
> Intel machines running LINUX, I'd like to hear about it.
>
> Matt
>

We run DB2 on Red Hat AS 2.1. The maximum buffer pool size per instance is
slightly less than 2G. That's sufficient for most databases. You can always
configure extended storage, if you need more.

I have not used AS 3.0. Maybe the limit has been increased in this release.

Bob Jones wrote:
> "Matthew Dauphinee" <mdauphinee@performics.com> wrote in message
> news:41acab23.0404070727.3cbd9aab@posting.google.c om...
>
>>Blair,
>>
>>That makes complete sense to me, but our management isn't very
>>interested in 64 bit computing yet. Painful.
>>
>>Well if anyone else is seeing upwards of 3.5GB bufferpools on 32 bit
>>Intel machines running LINUX, I'd like to hear about it.
>>
>>Matt
>>
>
>
> We run DB2 on Red Hat AS 2.1. The maximum buffer pool size per instance is
> slightly less than 2G. That's sufficient for most databases. You can always
> configure extended storage, if you need more.
>
> I have not used AS 3.0. Maybe the limit has been increased in this release.
>
>
I have ES 3.0, but do not have DB2 installed (I have only DB2 V6.1, and
I know I will have real dependency problems with it were I to try). When
I read Red Hat stuff, I infer that each process should be able to access
3.7 to 3.8 GBytes provided you have enough real memory and a chipset
(e.g., Intel E7501) to support it.

https://www.redhat.com/apps/WebForm/...paperfinal.pdf

implies it, but this link may require registration to see it.

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