topic Re: Memory segment error. in Operating System - HP-UX

Memory segment error.

Abdullatif M abdulla — Thu, 18 Feb 2010 07:06:54 GMT

shmsegCreateNewSeg(): ERRNO=12
Failed to get another shared memory segment (required size=100761552 bytes)
*** LIBSHMADM - IPC Error
shmAlloc(): Cannot create new SHM segment

The above error keeps generated some oftens in our billing servers using BSCS_iX. However rebooting the server solves the issue for some time then it appears again after 2 weeks or less.

Has any one came through such error and how to resolve it?

Re: Memory segment error.

Kapil Jha — Thu, 18 Feb 2010 07:36:03 GMT

do you see high memory usage in this time?

Seems ur memory is filled up and can no more allocate a chunck of required size.

BR,
Kapil+

Re: Memory segment error.

Horia Chirculescu — Thu, 18 Feb 2010 07:38:36 GMT

Hello,

You should check the kernel param.

shmseg and shmmni

Maybe try to increment those.

shmmax should be just about the size of your installed phys. memory

Use sam to check/modify those parameters.

Horia.

Re: Memory segment error.

Dennis Handly — Thu, 18 Feb 2010 08:39:58 GMT

>Has any one came through such error and how to resolve it?

You could be running out of 32 bit shared memory virtual address space.

What does "ipcs -ma" show?

Re: Memory segment error.

Abdullatif M abdulla — Thu, 18 Feb 2010 09:56:23 GMT

The platform is ia64 rx6600
Memory is 8GB.

top command output for memory is:
Memory: 3912832K (3838796K) real, 5650048K (5364812K) virtual, 1141256K free Page# 1/6

Kernal Values:
shmmax 3398046511104
shmmni 1024
shmseg 600

ipcs -ma output: attached

Re: Memory segment error.

Dennis Handly — Thu, 18 Feb 2010 21:27:17 GMT

>ipcs -ma output: attached

The sum is: Total: 2627789020 count: 47
This is more than 2 Gb and doesn't include any 32 bit shlibs or mapped files.

You have 32 segments all created by:
thurate bscs 3 67108864
They still have attached processes.

Re: Memory segment error.

Kapil Jha — Fri, 19 Feb 2010 02:20:27 GMT

I would still like to know if you had any memory crunch, when this error comes.

If it is then your process is not releasing the memory and in that case you have to check with vendor or maually clear the shared memory.

BR,
Kapil+

Re: Memory segment error.

Dennis Handly — Fri, 19 Feb 2010 03:03:21 GMT

>Kapil: I would still like to know if you had any memory crunch

You can run out of 32 bit shared memory virtual addresses before you run out of swap, 2 Gb vs 8 Gb. Unless using memory windows.

Re: Memory segment error.

Abdullatif M abdulla — Sun, 21 Feb 2010 05:15:12 GMT

Thanks for you replies, but today I have a new output for ipcs-ma it shows 0 values in NATTCH column.Do I have to clear these processes manually or the system will take care?

Regarding the memory crunch I dont notice any thing like this, but i will consider that in future.

Re: Memory segment error.

Dennis Handly — Sun, 21 Feb 2010 05:53:28 GMT

>I have a new output for ipcs -ma it shows 0 values in NATTCH column. Do I have to clear these processes manually or the system will take care?

You'll have to clean those up with ipcrm(1), unless the application in question wants to keep those segments around. But if so, there should only be a few of them.

Re: Memory segment error.

Abdullatif M abdulla — Mon, 22 Feb 2010 03:46:32 GMT

thanks, but if I go back and ask about (Failed to get another shared memory segment (required size=100761552 bytes)

What does it mean by required size=100761552 bytes ? where is this required size?

Re: Memory segment error.

Kapil Jha — Mon, 22 Feb 2010 05:10:14 GMT

@Dennis>> how do we find whether its using 32bit address space or 64 bit.
I could not find this out.

BR,
Kapil+

Re: Memory segment error.

Dennis Handly — Mon, 22 Feb 2010 09:11:46 GMT

>What does it mean by required size=100761552 bytes?

The application is trying to tell you the size it wants but didn't get.

>Kapil: how do we find whether its using 32bit address space or 64 bit.

You can do a file(1) on the executable, if 32 then it's 32. If 64, then you must use tusc to see if it wants to share a 32 bit address space, shmget(2) with IPC_SHARE32.

You can also look at the address to find if it is 32 or 64 bit.

Re: Memory segment error.

Horia Chirculescu — Mon, 22 Feb 2010 09:23:42 GMT

@Dennis

>You can do a file(1) on the executable, if 32 then it's 32.

Sample:

#file /oraprod/prod/oracle/product/805/bin/oracle
/oraprod/prod/oracle/product/805/bin/oracle: PA-RISC1.1 shared executable dynamically linked -not stripped

Can you tell from file() output it is 32 bit or 64 bit executable? What would be your guess on this executable?

Horia.

Re: Memory segment error.

Dennis Handly — Mon, 22 Feb 2010 09:39:59 GMT

>Horia: PA-RISC1.1 shared executable dynamically linked -not stripped

>Can you tell from file output it is 32 bit or 64 bit executable?

PA1.1 can only do 32 bit mode. For more, see my reply here:
http://forums.itrc.hp.com/service/forums/questionanswer.do?threadId=1160370

Re: Memory segment error.

Horia Chirculescu — Mon, 22 Feb 2010 10:30:14 GMT

@Dennis:>PA1.1 can only do 32 bit mode.

What do you think about this:

# file /oraprod/prod/oracle/product/805/bin/oracle
/oraprod/prod/oracle/product/805/bin/oracle: PA-RISC1.1 shared executable dynamically linked -not stripped

# su - ora9prod
You have mail.
$ sqlplus /nolog

SQL*Plus: Release 9.2.0.4.0 - Production on Mon Feb 22 12:24:47 2010

Copyright (c) 1982, 2002, Oracle Corporation. All rights reserved.

SQL> connect / as sysdba;
Connected.
SQL> exit
Disconnected from Oracle9i Enterprise Edition Release 9.2.0.4.0 - 64bit Production
With the Partitioning, OLAP and Oracle Data Mining options
JServer Release 9.2.0.4.0 - Production
$

Horia.

Re: Memory segment error.

Horia Chirculescu — Mon, 22 Feb 2010 10:52:19 GMT

.. and:

$ getconf HW_CPU_SUPP_BITS
64

Horia.

Re: Memory segment error.

Dennis Handly — Mon, 22 Feb 2010 10:56:13 GMT

>Horia: What do you think about this:
>oracle: PA-RISC1.1

Strangely this didn't change, still 32. :-)

>$ sqlplus /nolog
>Oracle9i Enterprise Edition Release 9.2.0.4.0 - 64bit

This claims to be 64 bit.

Re: Memory segment error.

Dennis Handly — Mon, 22 Feb 2010 11:00:34 GMT

>Horia: getconf HW_CPU_SUPP_BITS -> 64

Since this always returns "black" (on Integrity or 11.23), it is a waste of time using it, unless you have 11.11 and an obsolete PA1.1 box or one that still allows a 32 bit kernel.

Re: Memory segment error.

Horia Chirculescu — Mon, 22 Feb 2010 11:02:52 GMT

$ file /stand/vmunix
/stand/vmunix: ELF-64 executable object file - PA-RISC 2.0 (LP64)