[CentOS] CentOS 3 vs. CentOS 4 Memory Utilization

Sat Feb 10 17:04:33 UTC 2007
Les Mikesell <lesmikesell at gmail.com>

William Warren wrote:
> yes i did.  The 2.4x Rh kernels actually aren't right in their swapping 
> behavior.  it really nailed my samba server here at the house and caused 
> massive swapping and load issues on a friend's gaming server.  i don't 
> know what it is about RH's 2.4x kernels but they swap and won't give the 
> cache memory back.  I have more than 6 ipcop firewalls based on 2.4 
> kernels(not RH) and they won't swap unless you actually exhaust physical 
> memory.  The issue is the RH 2.4x kernels which for some reason continue 
> to swap even with 500 MEGS of cache memory available to take back.  2.6x 
> runs much better and actually obeys the swappiness commands.  Even the 
> various patches done by Rh on the 2.4x kernel never reduces this behavior.

I don't think I've seen that.  Here is a 'top' from an RH7.3 box whose 
uptime counter has rolled a couple of times so it has actually been 
running several years.

  10:57am  up 317 days,  6:56,  6 users,  load average: 0.07, 0.10, 0.09
213 processes: 210 sleeping, 2 running, 0 zombie, 1 stopped
CPU states:  5.1% user,  2.9% system,  0.0% nice, 91.8% idle
Mem: 2065404K av, 1988360K used, 77044K free, 0K shrd,  570124K buff
Swap: 1331128K av,  204848K used, 1126280K free      1158784K cached


That doesn't seem that bad and it's a 2.4.20-18.7 kernel.  It's not very 
busy now because it is a weekend.  I never see a lot of swap-in 
happening even when it is busy.

-- 
   Les Mikesell