High Swap Reservations

[Bill Holtgreive]

I have a HPUx 11.31 IPF server with 24GB of physical memory, 24GB of device swap and peuso-swap turned on. It is running 2 informix database that each startup in a 4GB shared memory segment. I am seeing the swap reservation far exceed the actual memory usage ( about 35GB) . Total physical memory use is at 10GB.
When I look at the swapinfo -tam I see:



# swapinfo -tam
Mb Mb Mb PCT START/ Mb
TYPE AVAIL USED FREE USED LIMIT RESERVE PRI NAME
dev 24576 0 24576 0% 0 - 1 /dev/vg00/lvol2
reserve - 24495 -24495
memory 23357 10970 12387 47%
total 47933 35465 12468 74% - 0 -

As soon as I stop the Informix database, the reservations go back down. On our 11.11 PARISC servers running Informix, the swap utilizations is typically more in line with the amount of physical memory in use.

What am I missing here?
Thanks - Bill

[Emil Velez]

When a process starts it reserves swap for its whole data and shared memory area. Whether the data portion is fully initialized or not.

You may want to look at your informix database parameters regarding the amount of cached info the database manages. That should determine the virtual memory size of the process.

[avizen9]

i believe there some parameter we can set in informix database end,

please get help to check the parameter from DBA for this.

I would like to know is this make you any problem? server get slow or something? let us know thanks.

[Dennis Handly]

>the swap utilizations is typically more in line with the amount of physical memory in use.

You aren't using swap, you only have it reserved. This is a good thing.
The total line says you are using 35 Gb of swap, with 10.9 Gb of memory used.