Shared memory Problem with 10.20

[Binu Raj_1]

Hi

We have a D370 Server which runs HPUX 10.20
mainly used for development and testing.

The configuration is as follows.

RAM 1GB
HDD space 80GB
Swap 1GB

It has Oracle 7.3.4 ,Oracle 8, topend and CCC/Harvest loaded. The Shared memory parameters are set to the following values.

shmmax 40000000
shmmni 300
shmseg 150

All the applications run properly but when
some users try to load some part of Oracle tables into shared memory using our software
the shmget() call fails at times and gives me a lot of trouble.

This occurs when the total shared memory exeeds around 300MB.

I am giving the error message from the user below.

We are encountering the shared memory problem on UNIX when mutilple topend posting
components are accessing the shared memory.This problem is encountered when
two or more topend users are accessing the shared memory area alongwith the rest of
BMRS users.This problem is encountered inspite of the memory being increased on
RSDEVUX.The topend system users for which the above problem is noticed is
as below :

1. testfir1
2. rndtrial
3. rndtest


Please find Attached Error Message :



shmget() failedbng_recv_data() failed
shmget() failedbng_recv_data() failed
bng_recv_data() failed
bng_recv_data() failed

Could some one please answer these questions for me.

1. What is the maximum limit of shared memroy which gets allocated using the
shmget() call in hpux 10.20?

2. Is there any kernel parameter I should alter to use at leaset 600 - 700 MB of RAM as shared memory?

Thanks in advance.

[James R. Ferguson]

Hi:

Check out:

http://docs.hp.com/hpux/content/KCparams.OverviewAll.html

...JRF...

[CHRIS_ANORUO · Accepted solution]

Hi Binu,

Set these values as follows:
MAXDSIZ=IGB
MAXTSIZ=1GB
NBUF=0
BUPAGES=0
DBC_MAX_PCT=25
DBC_MIN_PCT=5
SWAPMEM_ON=1
ALLOCATE_FS_SWAPMAP=0
SHMMAX=1GB
SEMAEM=16384
SEMMAP=1366
SEMMNI=1364
SEMMNU=2048
SEMVMX=32767


Use the information contributed in this attachment:

[Stefan Farrelly]

1. What is the maximum limit of shared memroy which gets
allocated using the shmget() call in hpux 10.20?

A. Maximum that be got from 1 shmget call = 1 Gb (if configured in kernel)

2. Is there any kernel parameter I should alter to use at leaset 600 - 700 MB of RAM as shared memory?

A. set shmmax to 600000 - 700000

[Vince Inman]

The previous replies are valid. However bear in mind that the maximum amount of shared memory that can be allocated system wide under 10.20 is 1.87 GB, this is an hp-ux limit. As well, the maxtsiz and maxdsiz parameters may come into play (text and data). It may be worth uping these parameters as well.