By using this site, you agree to our updated Privacy Policy and our Terms of Use. Manage your Cookies Settings.
440,947 Members | 1,594 Online
Bytes IT Community
+ Ask a Question
Need help? Post your question and get tips & solutions from a community of 440,947 IT Pros & Developers. It's quick & easy.

Memory and bufferpool issues

P: n/a
Hello,

I have a client running db2 udb 7.2 workgroup , FP10a on a Windows 200
server with 4GB of memory.
The database is 25GB big, but from that maybe 50% is current data. My issue
is that we are noticing that DB2 is only using about 100-150mb of RAM on the
server. This is a productrion machine with 50-75 of transactions a minute
on the database. Now flaming me about using W2k as the OS, we have running
similar testes on SUSE 9 with 4GB of RAM as well with the same results.

Here is the Kicker! ON the old database server with only 1GB of RAM, the OS
(Win2K or Linux) would use 600MB (and up) of RAM for the database.

WHAT IS GOING ON?

I have read about the theoretical 1.75gb (WINDOWS) or 1GB (LINUX) memory
restrictions for DB2. Is that the answer? Does DB2 7.2 run better on a
machine with less ram? I find that hard to believe....but if you DB2 genie
out there say that is the case...then i guess that is the case!

Any help would be greatly welcomed! Or at least guidance towards a possible
solution. Has anyone else come into such a problem? IS ESTORE the answer?

More info....

4GB RAM
2 XEON Hyperthread CPUs
Pleanty of HD space
WIN2k and SUSE9 tested.

One more thing, I have ran the configuration wizard and have even tried
manualy setting the settings to values that would seem appropriate, either
nothing happens or the RAM will shoot up to 1GB, however the CPU's shoot to
100% too (sounds like paging).

TIA everyone who helps

Chris
Nov 12 '05 #1
Share this Question
Share on Google+
4 Replies


P: n/a
"Yoyoma" <me@you.com> wrote in message
news:bk**********************@wagner.videotron.net ...
Hello,

I have a client running db2 udb 7.2 workgroup , FP10a on a Windows 200
server with 4GB of memory.
The database is 25GB big, but from that maybe 50% is current data. My issue is that we are noticing that DB2 is only using about 100-150mb of RAM on the server. This is a productrion machine with 50-75 of transactions a minute
on the database. Now flaming me about using W2k as the OS, we have running similar testes on SUSE 9 with 4GB of RAM as well with the same results.

Here is the Kicker! ON the old database server with only 1GB of RAM, the OS (Win2K or Linux) would use 600MB (and up) of RAM for the database.

WHAT IS GOING ON?

I have read about the theoretical 1.75gb (WINDOWS) or 1GB (LINUX) memory
restrictions for DB2. Is that the answer? Does DB2 7.2 run better on a
machine with less ram? I find that hard to believe....but if you DB2 genie out there say that is the case...then i guess that is the case!

Any help would be greatly welcomed! Or at least guidance towards a possible solution. Has anyone else come into such a problem? IS ESTORE the answer?
More info....

4GB RAM
2 XEON Hyperthread CPUs
Pleanty of HD space
WIN2k and SUSE9 tested.

One more thing, I have ran the configuration wizard and have even tried
manualy setting the settings to values that would seem appropriate, either
nothing happens or the RAM will shoot up to 1GB, however the CPU's shoot to 100% too (sounds like paging).

TIA everyone who helps

Chris

The main user of memory is the buffer pool(s). You said that you used the
configuration wizard but didn't say what the buffer pool size is.

As you noted, DB2 has memory limits on 32 bit operating systems, but that
does not mean that a system with less memory will have memory allocated for
DB2 (except on a percentage basis). Also, how much real memory is free
(available) before DB2 is started?

BTW, FP11 is now available.
Nov 12 '05 #2

P: n/a

"Mark A" <ma@switchboard.net> wrote in message
news:F0****************@news.uswest.net...
"Yoyoma" <me@you.com> wrote in message
news:bk**********************@wagner.videotron.net ...
Hello,

I have a client running db2 udb 7.2 workgroup , FP10a on a Windows 200
server with 4GB of memory.
The database is 25GB big, but from that maybe 50% is current data. My issue
is that we are noticing that DB2 is only using about 100-150mb of RAM on

the
server. This is a productrion machine with 50-75 of transactions a minute on the database. Now flaming me about using W2k as the OS, we have

running
similar testes on SUSE 9 with 4GB of RAM as well with the same results.

Here is the Kicker! ON the old database server with only 1GB of RAM, the OS
(Win2K or Linux) would use 600MB (and up) of RAM for the database.

WHAT IS GOING ON?

I have read about the theoretical 1.75gb (WINDOWS) or 1GB (LINUX) memory
restrictions for DB2. Is that the answer? Does DB2 7.2 run better on a
machine with less ram? I find that hard to believe....but if you DB2 genie
out there say that is the case...then i guess that is the case!

Any help would be greatly welcomed! Or at least guidance towards a

possible
solution. Has anyone else come into such a problem? IS ESTORE the

answer?

More info....

4GB RAM
2 XEON Hyperthread CPUs
Pleanty of HD space
WIN2k and SUSE9 tested.

One more thing, I have ran the configuration wizard and have even tried
manualy setting the settings to values that would seem appropriate,

either nothing happens or the RAM will shoot up to 1GB, however the CPU's shoot

to
100% too (sounds like paging).

TIA everyone who helps

Chris

The main user of memory is the buffer pool(s). You said that you used the
configuration wizard but didn't say what the buffer pool size is.

As you noted, DB2 has memory limits on 32 bit operating systems, but that
does not mean that a system with less memory will have memory allocated

for DB2 (except on a percentage basis). Also, how much real memory is free
(available) before DB2 is started?

BTW, FP11 is now available.

Thanks for the reply,

The buffer pool is set to the maximum alocated size. However it does not
realy allocate that amount of memory. is the limitation per bufferpool? I
mean if I manually create more than 1 bufferpool, can I have two 1.75GB
bufferpools?

I tried FP11 on our test server..didn't fix do anything memory wise.

Chris
Nov 12 '05 #3

P: n/a
"Yoyoma" <me@you.com> wrote in message
news:rh**********************@weber.videotron.net. ..
Thanks for the reply,

The buffer pool is set to the maximum alocated size. However it does not
realy allocate that amount of memory. is the limitation per bufferpool? I mean if I manually create more than 1 bufferpool, can I have two 1.75GB
bufferpools?

I tried FP11 on our test server..didn't fix do anything memory wise.

Chris

I don't know what "maximum allocated size" means. Buffer pools are defined
in a number of pages for a page size. Page size can be 4K, 8K, 16K, or 32K.
To figure out the amount of memory used for the buffer pools, multiply the
number of pages times the pages size. You should not define the buffer pools
(and other DB2 memory needed) higher than the amount of available real
memory for your system (or more than DB2 can address on that OS).

You can stop DB2 and look at the amount of available windows memory to
figure out how much is available for you to allocate to DB2. As I said, be
careful not to exceed the amount of real memory available (do not consider
virtual memory). Also, as you noted, only a portion of the 4GB can be
addressed by DB2.

You "may" be able to define two 1.75 GB bufferpools, but I don't think they
will use real memory and that is not good.

Remember, in addition to buffer pools, DB2 needs memory for other uses, so
take that into account. I would suggest that you use the configuration
wizard to help you with memory allocation.
Nov 12 '05 #4

P: n/a
1.75 GB is the limit on 32-bit AIX. You should be able to use 3 GB for
the bufferpool on Windows (requires Windows Advanced Server I believe
and larger pagers for the DB2 bufferpool and tablespaces - i.e. 8k).

Yoyoma wrote:
"Mark A" <ma@switchboard.net> wrote in message
news:F0****************@news.uswest.net...
"Yoyoma" <me@you.com> wrote in message
news:bk**********************@wagner.videotron.n et...
Hello,

I have a client running db2 udb 7.2 workgroup , FP10a on a Windows 200
server with 4GB of memory.
The database is 25GB big, but from that maybe 50% is current data. My


issue
is that we are noticing that DB2 is only using about 100-150mb of RAM on


the
server. This is a productrion machine with 50-75 of transactions a
minute
on the database. Now flaming me about using W2k as the OS, we have


running
similar testes on SUSE 9 with 4GB of RAM as well with the same results.

Here is the Kicker! ON the old database server with only 1GB of RAM,
the
OS
(Win2K or Linux) would use 600MB (and up) of RAM for the database.

WHAT IS GOING ON?

I have read about the theoretical 1.75gb (WINDOWS) or 1GB (LINUX) memory
restrictions for DB2. Is that the answer? Does DB2 7.2 run better on a
machine with less ram? I find that hard to believe....but if you DB2


genie
out there say that is the case...then i guess that is the case!

Any help would be greatly welcomed! Or at least guidance towards a


possible
solution. Has anyone else come into such a problem? IS ESTORE the


answer?
More info....

4GB RAM
2 XEON Hyperthread CPUs
Pleanty of HD space
WIN2k and SUSE9 tested.

One more thing, I have ran the configuration wizard and have even tried
manualy setting the settings to values that would seem appropriate,


either
nothing happens or the RAM will shoot up to 1GB, however the CPU's shoot


to
100% too (sounds like paging).

TIA everyone who helps

Chris


The main user of memory is the buffer pool(s). You said that you used the
configuration wizard but didn't say what the buffer pool size is.

As you noted, DB2 has memory limits on 32 bit operating systems, but that
does not mean that a system with less memory will have memory allocated


for
DB2 (except on a percentage basis). Also, how much real memory is free
(available) before DB2 is started?

BTW, FP11 is now available.


Thanks for the reply,

The buffer pool is set to the maximum alocated size. However it does not
realy allocate that amount of memory. is the limitation per bufferpool? I
mean if I manually create more than 1 bufferpool, can I have two 1.75GB
bufferpools?

I tried FP11 on our test server..didn't fix do anything memory wise.

Chris


Nov 12 '05 #5

This discussion thread is closed

Replies have been disabled for this discussion.