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Re: Excessive Paging in TRU64

Sameer Patel
Occasional Advisor

Re: Excessive Paging in TRU64

Hello,

Recently, I have noticed that there is lot of paging happening in my system. We have 2 COMPAQ Alpha ES40, each with 2 CPUs and 2 GB RAM and a COMPAQ RA8000 to support.

I am attaching herewith the sys_check output of both servers.

Please help urgently.

Thanks & Regards,
Trupti.
4 REPLIES
Erich Wimmer
Valued Contributor

Re: Re: Excessive Paging in TRU64

Hello,
you should first try to find out which processes are using the memory, f. e. with use of "ps vax" command. The VSZ column shows you the virtual size of the process, more interesting is the RSS column, which shows you the resident size of memory the process is using. "ipcs -ma" tells you about shared memory used.
Regards, Erich
Sameer Patel
Occasional Advisor

Re: Re: Excessive Paging in TRU64

Hello,

I am attaching herewith the output of ipcs -ma.

Request your help.

Thanks & Regards,
Trupti.
Erich Wimmer
Valued Contributor

Re: Re: Excessive Paging in TRU64

As you can see from the ipcs output your oracle database is using approx. 1 GB of shared memory, that means 1 GB is left for system, processes and buffer cache. If this is well sized depends on your application needs. 1 GB shared memory with 2 GB phys. memory available is a usual size. "vmstat -P" tells you more about systems memory usage, f. e. "ubc wired pages" shows you the buffer cache.
With "vmstat" you will see the paging activity, the column "pout" shows the no. of pages paged out to swap per invervall (ignore the first line of vmstat output, it is the sum since system boot). The column "memory free" shows the number of free pages (should be commonly above 128k).

I don't believe once can solve your problem by this forum in time, performance tuning is a complex job, you should involve your application provider or one of our help centers (hotline).

Regards, Erich
Erich Wimmer
Valued Contributor

Re: Re: Excessive Paging in TRU64

Made an error in previous reply, the "memory free" threshold for starting paging depends on your system settings and may be some other value than 128.
Erich.