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kernel upgrade, performance problem

Former Member
0 Kudos

Hi,

Recently I have done a kernel upgradation(ie 620 to 640 on windows 2003 adv server and SQL DB).

After placing the new kernel,the system did'nt come up.

I studied the trace files and all and found that there is an issue with address space allocation.

Then found some notes which says "if windows 32 bit OS has more than 2GB of RAM( we have 3GB RAM) this problem may occur and the solution is adding this parameter"em/address_space_MB=250" in instance profile.

After doing this the system came up and working fine.

Now the system is up and running from 4 days and the buffers got filled ,hit ratio is above 90%,swaps under control but the customer is complaining of slow response.

My question is, is the parameter "em/address_space_MB=250" has anything to do with performance?

If so, what can be the remedy for this?

except adding this parameter nothing has been changed.

And one more thing is i did'nt run SGEN as there is not enough space and after 4 days the loads should have been generated by normal operation ,I think.This is may be one problem area.

Any help is appreciated.

Thanks & Regards,

Bapujee Naidu

Accepted Solutions (0)

Answers (1)

Answers (1)

JPReyes
Active Contributor
0 Kudos

Hi Bapujee,

I got 4 GB in mine and i got the parameter em/address_space set to 512 and no performance problems... maybe just increase it a bit maybe to 368

Let me know how it goes!

Juan

Former Member
0 Kudos

Hi Juan,

But is this parameter related to performance in any way?

Regards,

Bapu

JPReyes
Active Contributor
0 Kudos

Hi Bapujee,

I found this "The parameter em/address_space specifies how much extended memory a user context gets"

See this i found it very helpful, http://help.sap.com/saphelp_nw2004s/helpdata/en/84/7ed387d81f11d188be0000e83539c3/frameset.htm

So maybe you should use 512

Regards

Juan

Former Member
0 Kudos

Hi Juan,

the link says 512 is for 64bit windows.

But on 32 bit with this default parameter (em/address_space_MB=512),the SAP system will not come up even.

So i am forced to change it to 250 as specified by a note.

Any way thanks for your help and I will try to explore about this parameter.

Regards,

Bapu