OOM Killer Invoked after SLE12 Upgrade

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Environment

SUSE Linux Enterprise Server 12

Situation

After upgrading from any SLES11 to any SLES12 version, the system became unstable and was running out of memory. Messages about the out of memory killer being invoked were observed.

2017-11-08T18:05:25.713556-02:00 db2p121 kernel: lsof invoked oom-killer: gfp_mask=0x14280ca(GFP_HIGHUSER_MOVABLE|__GFP_ZERO), nodemask=0, order=0, oom_score_adj=0

The sysctl -a | grep swappiness shows:

vm.swappiness=0

Resolution

You can add memory to the server and/or Increase swappiness to 5 or 10 to allow some swapping.

Edit /etc/sysctl.conf and add:

vm.swappiness=10

Reboot the server.

Cause

Swappiness is handled a bit differently in SLE12. In SLE11 a little bit of swapping was allowed even if vm.swappiness=0, but in SLE12 no swapping is allowed when vm.swappiness=0

Additional Information

2017-11-17: Jason Record - Initial Document

Disclaimer

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