swap and oracle

[GLOT]

Hello all,

I'm running a L2000-44 with 2gb RAM.
Yesterday, we encountered one oracle error associated to the new connections :

TNS-12500: TNS:listener failed to start a dedicated server process
TNS-12540: TNS:internal limit restriction exceeded
TNS-12560: TNS:protocol adapter error
TNS-00510: Internal limit restriction exceeded
HPUX Error: 12: Not enough space

It seems that oracle listener sannot swap space for new processes.
Here are the result od swapinfo command :
# swapinfo -tm
Mb Mb Mb PCT START/ Mb
TYPE AVAIL USED FREE USED LIMIT RESERVE PRI NAME
dev 1024 0 1024 0% 0 - 1 /dev/vg00/lvol2
reserve - 1024 -1024
memory 1529 1263 266 83%
total 2553 2287 266 90% - 0 -

At each new oracle connection, for example with sqlplus tool, the total free memory decreases of 12 Mb, that is very high and strange !

Here are others informations :
dbc_max_pct 20 - - -
maxdsiz 262144 - 0-655360 Pages -
maxdsiz_64bit 524288 - 256-1048576 Pages -
maxfiles 60 - 30-2048 -
maxfiles_lim 1024 - 30-2048 -
maxssiz 2048 - 0-655360 Pages -
maxssiz_64bit 2048 - 256-1048576 Pages -
maxswapchunks 16384 - 1-16384 -
maxtsiz 262144 - 0-655360 Pages -
maxtsiz_64bit 262144 - 256-1048576 Pages -
maxuprc 500 - 3- -
maxvgs 10 - - -
netmemmax 0 - - -


Can you advise me ?

[T G Manikandan]

Everything is used

Memory completely used.swap everything is reserved.
That's the problem.

At present you have 1gb of swap allocated.
increase another 1 to 1.5 gb of swap to resolve the problem.

you should note that the swap allocated is used for reservation completely.

[Stefan Farrelly]

Youve got 2Gb of RAM but only 1GB of device swap ? That means you can only really use 1GB of RAM - you MUST add a second device swap of 1GB to take the device swap total to 2GB. (add it to /etc/fstab then use swapon -a) or use SAM to add it.

[Jeroen Peereboom]

Well,

if the swapspace is really used, you'd better buy additional RAM first for better performance?!

I remember a (recent) thread stating that 2GB isn't that much for Oracle 9i. But I cannot find it...

JP.

[Jeroen Peereboom]

I found it:
http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=376026

But do read all replies, because maybe you have a configuration problem...

JP.

[GLOT]

Hello all,

Thanks for your answers.
I agree I need to increase the swap are.

For my understanding, I don't understand why the %USED of swap dev is already equal to 0 and why a new oracle connexion takes 12 Mb in the memory zone of swap.

Thanks

Result of swapinfo command.
# swapinfo -tm
Mb Mb Mb PCT START/ Mb
TYPE AVAIL USED FREE USED LIMIT RESERVE PRI NAME
dev 1024 0 1024 0% 0 - 1 /dev/vg00/lvol2
reserve - 1024 -1024
memory 1529 1164 365 76%
total 2553 2188 365 86% - 0 -

[T G Manikandan]

I am not sure whether you are asking for the reserve column of the swapinfo output.

Any process before execution in the Memory reserves some space in swap.this is because if incase the process is to be swapped then it will use that space.

Now you can see that the reserve column is full.
So no more swap is there for to swap processes/pages or reserve memory.For that to happen you have to increase swap.

[Steven E. Protter]

Swap is kind of low.

I'm running a bunch of Oracle instances on very similar hardware.

My swap setup is thus(from the A. Clay School):

One primary swap area equal to half of RAM. This is the minimum for a dump area anyway. When only this area is being used the system is very fast.

A larger secondary swap area equal to between 1.0 and 1.5 times ram depending on circumstances. This has only been used during load testing and the machine is pretty responsive when it happens.

You have the horses, now you need to set up swap propoerly.

I recommend device swap unless you are in a real pinch. Adding device swap with sam or command line requires a boot to activate it.

SEP