HD Install :: Swap partition - how big?

Okay - now that I've installed to my HD, I'm thinking i should have made a swap partition as performance can be slow on tis old notebook (I think 8mb RAM but not sure).

Question 1: How do I get system info of my box regarding RAM, CPU spec etc?
Question 2: How do I figure out the ideal swapfile / partition size for the same machine?
Question 3: Can I use something like fdisk to add a swapfile nondestructively or will this require a reinstall from scratch?

If you really only have 8 MB, I would suggest that you try Basic Linux (http://distro.ibiblio.org/pub/linux/distributions/baslinux/) as DSL requires more than 8 MB (I'm not sure, but DSL may be possible to boot into command line).

Q1:
Download tomsrtbt (http://www.toms.net/rb/), create a diskette, boot and run these commands:
free
more /proc/meminfo
more /proc/cpuinfo
dmesg | more
fdisk -l

Q2:
An old rule of thumb says that swap should be twice physical ram.

Q3:
If there is some free space on the disk not used for a partition, it is possible. Otherwise, no.

Thanks.

Looks like I actually have 36Mb RAM in this thing and around a 100Mhz CPU. Seems to be zipping along reasonably well after adding some 74Mb or so swap.

The general rule of thumb with swap is 2x your ram.
I've found alot depends on the size and number of apps you have open.
for a machine with 36 meg I would advise at least 128 m, 256 m if you have the space, cause you're gonna run out of real ram pretty quick.
If you;re doing ok, tho, I would leave it till a problem shows up and then make the change.
Also be sure you are using the swap, if it wasn;t formatted as swap when you booted, it won;t be using it.
To format for swap open a root window, or add sudo in front of this:
mkswap /dev/hdax

where you would substitute your actual hda device number.
The when done issue:
swapon

or sudo swapon if you don;t have root auth.
It will start using the swap right away, and will automatically use it on each subsequent reboot.
Good luck!

original here.