Swap problem

[karthiknarayan]

this is my glance output

Total VM: 7.8gb sys Mem : 1.7gb
Active VM 1.3gb Buf Cache : 8.0gb
user Mem : 4.9gb

Free Mem : 1.5gb

Due to this my system ram gets 100% full and iam forced to reset the server to start new proces.
kindly adive what to do. i have psedu swap enabled.

[Mike Keighley]

Memory tuning is a bit of a black art.

It depends on all sorts of things which we don't know, such as:
Total physical memory
No. of users
Application mix
Size of the working set of each application
etc. etc.

However the thing which sticks out is
Buf Cache: 8.0 gb
... which sounds quite high.

Reducing your maximum buffer cache size should free up more memory for user processes.
I believe the kernel tunable "dbc_max_pct" defaults to 50%.
Try reducing it in 10% increments, and see if that helps.

Reducing it too far might impact performance because your filesystem cache will be smaller.
However, ram for applications is usually more important than ram for caching.
Many systems reportedly get by with dbc_max_pct 10, especially if they are doing client/server stuff, as opposed to file- server stuff.

Other areas you might look at include looking for memory leaks, zombie processes, tuning the system table sizes, tuning swap, throwing more physical ram at it etc.
... but I would start with dbc_max_pct.

[Steven E. Protter]

Shalom,

Sounds like swap may not be working properly.

swapinfo -tam

See what it reports.

You may wish/need to remove the current swap and rebuild it using command line utils or sam.

You buffer cache is consuming a lot of memory and I endorse the prior post recommending it be reduced.

SEP