Bug#620993: general: Lenny 2.6.26-2 has noticably increased swap usage, tho not swap thrashing
Swap usage prior to 2.6.26-2 upgrade was a relatively constant 0
Post 2.6.26-2 upgrade the usage is usually up into 300MB, not actively swapping however and doesn't seem to be affecting performance, but nagios is none to happy about swap being used.
The problem seems relegated to a handful of machines, although there may be some usage pattern I'm not seeing but otherwise there is no difference between systems that are "swap happy" and those where swap stays 0, same make/model, same build configuration, packages, client code, etc.
Like I mentioned, it doesn't seem to impact performance, but it is certainly a change from the norm.
See this on about 8 systems out of a couple hundred, and the same 8 will almost always start using swap slowly over time until a plateu is reached of around 300-500MB, depending on the system.
-- System Information:
Debian Release: 5.0.8
APT prefers oldstable
APT policy: (500, 'oldstable')
Architecture: amd64 (x86_64)
Kernel: Linux 2.6.26-2-amd64 (SMP w/8 CPU cores)
Locale: LANG=C, LC_CTYPE=C (charmap=ANSI_X3.4-1968)
Shell: /bin/sh linked to /bin/bash