Device Swap and pseudo-swap

[Bill Schultz_1]

L2000 running 11.00

2GB physical Memory
2GB device swap

Glance shows this:
Swap Device Type Avail Used Priority
/dev/vg00/lvol2 device 2.0g 0 1
pseudo-swap memory 1.5g 578 na

Swapinfo basically shows the same thing.
Mb Mb Mb PCT START/ Mb
TYPE AVAIL USED FREE USED LIMIT RESERVE PRI NAME
dev 2048 0 2048 0% 0 - 1 /dev/vg00/lvol2
reserve - 669 -669
memory 1531 579 952 38%
total 3579 1248 2331 35% - 0 -


Here are the kernel paramaters:
maxswapchunks 1024
swapmem_on 1
swchunk 2048
dbc_max_pct 10
dbc_min_pct 5
maxdsiz_64bit 0x0000000040000000
maxtsiz_64bit 0x0000000040000000
shmem 1
shmmax 1073741824
shmmni 200
shmseg 120


Here is my question. Why is this system not using device swap? It is running an Oracle Database for Remedy and it having some "hanging" problems. Remedy says it is possibly a memory issue.

I am just trying to figure out why device swap is never used. Glance also shows that memory is 71% utilized right now.

Any help would be greatly appreciated.

[A. Clay Stephenson]

The short answer is because it's not yet needed --- at least at the moment this swapinfo was run. There is really no point in having pseudoswap enabled when you have at least as much swap space configured as you have memory. It's really intended for those systems which have less swap space than memory and especially for those systems which have lots of memory and little swapspace.

[doug mielke]

I'd look at the Oracle SGA size. You can get all the classic low memory symtoms, if this is too small (if the dbsae evn starts)

You are limited depending on version, but I'd look there 1st.

[Bill Schultz_1]

Can you point me in the direction of where I would find the SGA setting?

When I look at Shared memory I am find this:

oracle oinstall 11 350715904

Thanks

[Bill Schultz_1]

Sorry Doug...

I left out the table headings that I showed..


CREATOR CGROUP NATTCH SEGSZ
oracle oinstall 11 350715904

[Stefan Farrelly · Accepted solution]

Your Oracle SGA is set to 350MB of shared memory, which seems fine. We run all our oracle databases from 200-600MB. You could increase it seeing has you have a few hundred MB of free RAM.

Its set in the init.ora file for the database. You need to find this file, its usually in a directory like;
/apps/oracle/product//dbs/init.ora

Take a look at this thread on how to set the SGA size in this file, you need to be sware of multiple values;
http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=93779

[Bill Schultz_1]

Thank you for your help. Now that I know the SGA is 350 MB, I need to find out why oure shmmax is set to 1GB. No reason to set it that high since Oracle is really the only thing running.