Swap space not being used?!

cathectic · 02-11-2005, 10:31 AM

If your machine isn't crashing, then you have no problem. This is just a difference between how Windows and Linux handle swap (page file in Windows) and system memory.

In Windows the preference is to use the page file on the hard drive, rather than fill up system memory.

In Linux the preference is to use the system memory/RAM first, before touching the hard drive. After all, RAM is *much* faster than your hard drive, so why do you want to be swapping in and out of memory from the hard drive if it can be avoided?

shilo · 02-11-2005, 12:45 PM

cereal83:

cathectic is right. One question, how do you know that "memory is at 99%"? An example:

Code:

shilo@shilo2:~$ free -m
             total       used       free     shared    buffers     cached
Mem:           504        498          5          0         98        169
-/+ buffers/cache:        230        273
Swap:          486          0        485

If you see something like this, you may be thinking that there is only 5M free memory (memory is at 99%). So you think you are about to run out. Not so. The memory used by buffers/cache is easily reclaimed by applications as need. It will still be awhile before I need any swap.

cereal83 · 02-11-2005, 07:49 PM

Shilo, well I went to menu then System then Info Ceneter and went to memory and it's a GUI of my total memory, Physical memeory and swap space the total memeory was at 99% and sthe swap was at 0% (not being used)

I dunno maybe it is working but I just dunno how it works

major.tom · 02-12-2005, 12:50 AM

I wouldn't be alarmed that your system is not using any swap. As long as `free` and `cat /proc/swaps` shows your system recognizes the swap partition there's no good reason Slack wouldn't grab it if it needed to.

A short while ago, I was using ext3 as my filesystems. At that time, my system used to use some swap. But (using a 2nd hard drive) I converted everything to reiserfs and also increased the size of the swap partition (512 MB RAM, 512 MB swap). Now my #'s look very much like Shilo's above. I didn't think that switching filesystems would make much difference to memory use, but I can't find another explanation for it.

I haven't seen it touch swap in ages. But the system is running well, so what do I care? As long as you have no stability issues (lockups/reboots) it should be just fine.

Garry