Debian's recommendation for the size of the swap.
Debian's recommends (in its FAQ and the installation guide) to have about 50MB
of swap file.
I am using 50MB only as a representative number. I know it is also saying that
(1) Linux accept up to 128MB for a single swap partition (2) There is (was) a
rule of thumb to have a swap size as twice as the RAM the machine has (3)
Having more RAM reduces the needs for swap.
I think that this recommendation should be raise to the full 128MB that Linux
accept for a single swap size, together with the saying that it can work with
much less swap, that it is hard to determine a single number when almost each
installation is different on its use and future needs, etc.
My reasons are:
1) Application are getting bigger in their memory needs (netscape, xemacs,
image proccessing, and more). And the rate that the applications are getting
bigger seems to exceed the rate the memory chips are getting larger and
2) Disk sizes are getting larger, so sparing as much as 128MB for swap size
today is much less painfull and much more cheaper then sparing 50MB couple of
3) Resizing disks partitions when someone needs more swap is a problmatic
process, and using swap files are not recommended.
4) Restaring an application seems to require more and more time.
While saying all that, I am taking my machine a an example:
[07:04:06 shaul]$ free
total used free shared buffers cached
Mem: 38344 37732 612 17868 208 8984
-/+ buffers/cache: 28540 9804
Swap: 48380 43608 4772
My machine is used as a desktop computer for a single user. It has only modem
connection to the internet. Still, it uses a considerable amount of its memory
resources. Then what am I doing with all that memory resources ?
The answer is that I am using a 3x3 pages on my display, and tend to keep the
programs open on one page while I am switching to another. I find it more
comfortable to switch to a different display page then to use one page and
open and close the programs that I want. Therefor, I am using "simultansiouly"
a total of about 6 xterms (about one for each display page), one copy of
netscape, one xemacs window, one DDD window, and 3 TkMan windows.
A little experiment that I did show (?) that iconifying most of these windows
has little effect on the memory usage.
Does all this make sense ?
Perhaps Debian should make a small survey among its users about the size of
the swap size they are using ?