Bug fix for Linux on System z extensive swapping

Recently there has been a small bug fix for the swap behavior of Linux on System z. The following problem has been observed by several users:

The first time Linux started swapping it was doing so really extensively even though only a small amount of additional memory was needed. Depending on the disk speed and size of the swap space this can take a while.

The fix is included in

• RHEL 5.7.z update 2.6.18-274.11.1
• RHEL 6.2 base 2.6.32-220
• SLES 10 SP4 kernel update 2.6.16.60-0.91.1
• SLES 11 SP1 kernel update 2.6.32.45-0.3.1

and will be available for the other distros in the future as well.

As the system becomes totally unresponsive during that period I really recommend to get this fix installed if your system has more than a minimal swap attached and you are experiencing heavy first time swapping now and then. Contact your distribution partner or service provider in this case to get a temp fix.