Memory issues on Linux

HCL Domino Domino Forum
1

Hello,I’m running an 8.5 server on a vps Linux server, running CentOS 5.2 64 bits (technically equivalent to RHEL 5.2 64 bits). The box has 2GB RAM available. The server is quite unstable; it often crashes with the error printed below, but I have also seen the http and/or server process go to 100% CPU. I have tried several combinations of ConstrainedSHM and other memory related notes.ini settings, but haven’t found the winning combination yet. Any recommendations as to how I should configure memory for this server?

I also wonder whether tunekrnl is able to set the right values in the kernel areas it’s supposed to optimize; if I start the server manually, I get ‘permission denied’ errors there:

Error - can’t open /proc/sys/fs/file-max.

    errno: 13

    Permission denied

Error - can’t open /proc/sys/kernel/shmmax.

    errno: 13

    Permission denied

Error - can’t open /proc/sys/kernel/sem.

    errno: 13

    Permission denied

Error - can’t open /proc/sys/net/ipv4/tcp_fin_timeout.

    errno: 13

    Permission denied

Error - can’t open /proc/sys/net/ipv4/tcp_max_syn_backlog.

    errno: 13

    Permission denied

Error - can’t open /proc/sys/net/ipv4/tcp_tw_reuse.

    errno: 13

    Permission denied

Error - can’t open /proc/sys/net/ipv4/ip_local_port_range.

    errno: 13

    Permission denied

Can anyone tell me what values should be in these files, so that I can compare them?

This is an example of the error sometimes observed on the system:

** Error attaching to shared memory [loc=MapSharedRegion,error code=12,ptr=ffffffff] – check Notes configuration variables (ConstrainedSHMSizeMB, PercentAvailSysResources).

Thread=[03976:00002–173762336]

Stack base=0xFFCC166C, Stack size = -1172 bytes

PANIC: Cannot attach to shared memory region, due to insufficient access (probably owned by another user or group)

Stack base = 0xffcc166c, Stack size = 332 bytes

Fatal Error signal = 0x0000000b PID/TID = 3976/-173762336

4/8/2009 2:19:13 Running NSD

4/8/2009 2:19:13 Fault cleanup is in progress

4/8/2009 2:19:13 Too many crashes, restart disabled

4/8/2009 2:19:13 Terminating tasks

4/8/2009 2:19:27 Freeing resources

4/8/2009 2:19:27 Termination completed

Thanks in advance, kind regards,

Gerco

2

Subject: memory issues

Please verify that tunekrnl is owned by root and is setuid root as well.

The error message:

** Error attaching to shared memory [loc=MapSharedRegion,error code=12,ptr=ffffffff] – check Notes configuration variables (ConstrainedSHMSizeMB, PercentAvailSysResources).

means that for some reason you are having issues with shared memory segments. This could be due to allocating too much shared memory for some reason or to issues with the maximum # of segments we are able to create.

An nsd should have been created for the crash so if you can attach that it would help. Inside the nsd will be information about your system and settings as well as about domino and where it is at (such as how much shared memory has been allocated from the OS).

Thanks

kenbo

3

Subject: Tunekrnl checked, no nsd

Ken,Thanks for responding! The tunerknl settings look valid to me:

[root@box linux]# ls -l tunekrnl

-r-sr-xr-x 1 root daemon 52653 Dec 6 02:05 tunekrnl

Unfortunately, there’s also an issue with NSD. It doesn’t run properly when the box crashes so I usually get the warning that I should enable NSD on the server document, which already is enabled. Every now and then though, a valid NSD is created, and those usually deal with the http task. If needed I can send it to you?

Thanks and kind regards,

Gerco

4

Subject: Permission Denied Error…/proc/sys/kernel/

Hello,I am also having similar issue and cant seem to resolve the issue. I am running a version release of 7.0.1. I have checked for the permissions and the my memory size and everything seems fine.Please can someone assist.