How do you ajust Virtual Memory?

Hawky · 03-06-2007, 08:52 AM

My wife's laptop is very, VERY slow running openSUSE 10.2 due to a low RAM size.

To adjust the virtual memory size in windows is a 2 second job, but I can't seem to find it in SUSE. Any ideas?

Thanks

tredegar · 03-06-2007, 09:10 AM

Quote:

To adjust the virtual memory size in windows is a 2 second job, but I can't seem to find it in SUSE. Any ideas?

Linux's "Virtual Memory" is called "swap", and is the size of your swap partition. Your /etc/fstab will tell you which partition is your swap partition.

Increasing swap space is unlikely to help you, because it is slow.

So you can improve performance by:
Adding more RAM
Stopping unnecessary "services" running in the background.
Running a lightweight distro,
Running a lightweight window manager

jlliagre · 03-06-2007, 09:44 AM

Quote:

Originally Posted by tredegar

Linux's "Virtual Memory" is called "swap"

More precisely, virtual memory is (roughly) the sum of RAM and swap space (made of swap partitions and/or swap files).

You are true telling increasing the swap won't help improving performance.

The only point of adding swap space with Linux is to improve reliability in case of virtual memory exhaustion.
Otherwise, random processes may crash because of the "OOM killer".

Hawky · 03-06-2007, 09:48 AM

ah, so that's what the swap is. I've always created one whenever I install a distro, but I've never really looked into what it actually does.
I keep telling her to buy some more RAM, but she won't have it. I guess I'll have to buy her an early Christmas present.

Thanks guys.

osor · 03-06-2007, 10:50 AM

In addition to adjusting the virtual memory “size”, you can also adjust the amount that gets used. There is a kernel parameter called “vm.swappiness” which holds a number between 0 and 100 and indicates to the kernel how conservative you want your swap usage to be (0 = no usage, 100 = very liberal usage).