CC / Rhugga, On Thursday 09 December 2004 08:28, Rhugga wrote:
I have a vanilla installed SLES9 system with no applications runnig as of yet. Everything is default (except I disabled the ldap server and set the default run level to 3 so no X processes are running either)
...
When the system first booted memory usage for around 500mb (still high) but during it's 2 hour of uptime it has grown to 728mb, by itself, with no system activity.
This is as it should be. The system does not try to maintain a large margin of unused RAM, since that is nothing more than waste as a policy. Instead, it keeps a lot of discardable resources (disk blocks, mostly) in RAM and manages any RAM not required by applications as a variable-sized cache. This is a change from older Linux kernel behavior, but I'm not sure how far back the change of policy goes.
When I look at 'ps -aux' there doesn't seem to be any single process using a large amount of memory.
They're not, and that's the sign that all is well. Should one or more applications request memory, the kernel will abandon enough of the cached disk contents to fulfill those applications' requests.
This system is a dual Xeon, 1gb memory, SysKonnect gigabit NIC, 2x36gb SCSI disks with 3 Raid 1 devices. (/boot, swap, and /)
This just seemed like a large amount of memory being used with no applications running other than the default services.
The only fix required is that you adjust your intuition about a healthy system's resource utilization patterns. You want to start to worry when the swap activity goes up, not until. I have a single-CPU (w/ hyperthreading) and one gigabyte of RAM and I see very similar patterns and my machine runs very smoothly.
Thanks for any info, CC
Randall Schulz