topic Database Related in Operating System - HP-UX

Database Related

Faizer Jameel — Sat, 30 Nov 2002 13:32:17 GMT

Gentlemen;

The Scenario,
The HP Vclass system has the following Oracle Production Systems running.
3 Instances of Oracle 8 databases
2 Instances of Oracle 8i databases
2 instances of Oracle Financials 11.5.7
Server Configuration
Memory : 4gb Swap Space 8gb Operating System HPUX11.0
4 cpus @240Mhz
The available memory when these systems are running is approximately 650MB
Problem:
When we issue the command to start the 3rd Instance of the Oracle8i Production database we get the following error message
HPUX Error: 12 'Not Enough Space'

Please help ....

Re: Database Related

Robert-Jan Goossens — Sat, 30 Nov 2002 14:39:04 GMT

Hi,

Take a quick look at following link.

http://forums.itrc.hp.com/cm/QuestionAnswer/1,,0x90c153921f1ad5118fef0090279cd0f9,00.html

Hope it helps.

Robert-Jan.

Re: Database Related

T G Manikandan — Sat, 30 Nov 2002 15:42:49 GMT

HPUX error 12 not enough space is due to the insufficient memory on the system for the new instance.

Do a swapinfo -ta
to check the amount of memory used and the amount of swap space used on the system.

Probably the new instance does not enough memory to startup.

What is the SGA size of the new instance?
What is the shmmax parameter value on the system?
What is the size of the buffer cache on the system?
dbc_max_pct and dbc_min_pct.

My approach would be like,

1.check the amount of buffer cache on the system.

Your machine has 4GB.Then the value of dbc_max_pct=8 and dbc_min_pct=4 should be fine.
By default the value is 50 i.e.half of the memory is allocated for buffer cache.
Also with Oracle running it has its own buffer cache.

2.What is the value of the shmmax parameter?
Try increasing it.
check this size.

3.What is the value of SGA for the new instance.YOu can reduce the size of SGA for the new instance and try starting up.

If all the above does not work.
Then try using Glance to check the processes memory usage.
You can also use
UNIX95= ps -e -o ruser,pid,vsz=Kbytes|more
to check the process memory usage and stop the unwanted processes running.

4.YOu can also go for a multithreaded (MTS) instead of dedicated instance for the Oracle.
This should reduce the existing database memory usage.
Because the 8i version,each client connection takes around 30MB incase if you are running under dedicated server model.

check things out and revert

Re: Database Related

Wodisch — Sat, 30 Nov 2002 19:36:49 GMT

Hi,

what I cannot see in your posting is wether your Oracle instances are 32bit or 64bit?
With 32bits they can only use a SHARED 1GB maximum memory segment all together :-(
Or do you use "memory windows", i.e. the command "set_memwindow(1M)"?
Then be careful that all your LISTENERs must be prefixed with the appropriate "set_memwindow(1M)" command, too...

FWIW,
Wodisch

Re: Database Related

harry d brown jr — Sun, 01 Dec 2002 04:10:09 GMT

4Gb of memory, even 8GB of swap, isn't a lot of memory for the resource pig "ORACLE", especially for 7 Instances! I don't even think 16GB would satisfy that BEAST. Plus, with 4 cpu's, you don't have the horse power to swat a flea. I sure hope you have one hell of a great IO sub-system.

Did I hear someone say "superdome" ??

live free or die
harry

Re: Database Related

Faizer Jameel — Sun, 01 Dec 2002 09:13:48 GMT

Thankyou for the replies;
I am also attaching an output from swapinfo and kmtune -l .
In addition the Oracle installation is a 32 bit application
The SGA is 256000
Shared pool size = 300000000

Hope by perusing these it would clear the requirements to provide me a solution.

Re: Database Related

Faizer Jameel — Sun, 01 Dec 2002 09:15:23 GMT

The Kernel paarameter output

Re: Database Related

harry d brown jr — Sun, 01 Dec 2002 12:29:05 GMT

Faizer,

First thing: you need to change Parameter: dbc_max_pct to 8% (it's 20% now) and dbc_min_pct to 4% (which is 5% now).

live free or die
harry

Re: Database Related

T G Manikandan — Mon, 02 Dec 2002 02:56:01 GMT

YOu should increase your

shmmax
maxdsiz
maxdsiz_64

kernel parameters.

These parameters are definitely very small.

Increase them to 1GB.

Thanks

Re: Database Related

Ravi_8 — Mon, 02 Dec 2002 06:21:32 GMT

Hi, Faizer

I was facing the same problem with 3 oracle instances, after increasing the swap the database was working satisfactorily

Re: Database Related

Ravi_8 — Mon, 02 Dec 2002 06:24:03 GMT

memory was 1 GB and swap 2 GB, later i increased the swap to 3 GB.

Re: Database Related

Alexander M. Ermes — Mon, 02 Dec 2002 06:29:50 GMT

Hi there.
There are a few things, that you can do.
Make an analysis, how much of the SGA of each database is really used.
After this decide, whether you can reduce the SGA size by lowering the database buffers, the shared poolsize or something else.
Do this database by database.
If you cannot reduce the size, then you have to decide, whether you need performance or not.
if you need performance, try to get another 2 GB of RAM, otherwise enhance your swap space.
Just my 2 ct
Rgds
Alexander M. Ermes

Re: Database Related

Faizer Jameel — Mon, 02 Dec 2002 09:29:23 GMT

Gentlemen,
Thankyou for the time that you all ahve spent on this issue. Definitely all suggestions are very valuable and have been taken into account.
This has also given me an indepth knowledge on this matter.

The resolution I tried was quite simple. I shutdown the server[ poweroff] and restarted, after that I was able to bring up all my instances without any problems.

Once again Thankyou everyone.

Re: Database Related

Philippe Cussigh — Tue, 03 Dec 2002 08:17:32 GMT

Hello,

Just an additionnal comment.
As you are using 32 bits Oracle you are obviously facing the 1.75 Gb limit, which in fact means two limits :
- The total size of shared memory used
- The fragmentation of the memory

If the issue has been solved by rebooting the system it is possible you faced the second issue.
With Hp-ux 11.0 you have no best_fit policy for memory allocation, so the situation can degrade with time.

You should check the memory allocation with tool like shminfo which display a detailed map of the available shared memory in the 1.0 and 0.75 quadrant. shminfo is a usefull but unsupported tool you can get from HP support.