I quote from that thread:
The standard rule is usually memory x 2. (But that is more a Solaris superstition than anything else.)
This always struck me as the most stupid rule of thumb I'd ever heard of. With this metric, systems which precisely need swap the most (low-RAM systems) get the least of it, and those that need it the least (those with gigs of RAM) get tons of swap they don't need. I don't know how this keeps perpetuating, as it should be plainly brain damaged to anybody who thinks about it for a couple of seconds, but somehow it does.
end quote.
The writer is correct, but the underlying assumption is that machines with big RAM are doing big jobs. So the memory*2 rule still holds iin general. However, if you know the characteristics of your work load e.g. giant compilations, lots of large images to be edited, you may be able to estimate better.
N.B. the behaviour of 2.4.x is slightly weird. If you are not actively swapping your will not need any more than with 2.2.x; if you are actively swapping you will need rather more.
On 29-Nov-01 Adam Bower wrote:
From: "Ricardo Campos" corez23@linuxmail.org To: abower@thebowery.co.uk CC: main@lists.alug.org.uk Subject: Re: [Alug] Re: previous post, Slackware 8 and Debian not `seeing' the CD drive Date: Thu, 29 Nov 2001 12:51:55 +0000
Not with 2.4.* kernels the vm needs either at least 2x swap to RAM or no swap at all, if not you may/will see performance problems on your
machines.
Hmm... methinks not. I have 512MB RAM (& kernel 2.4.3), and only 133 MB swap space (to use during the install), and find no performance problem in any way. In fact the opposite! There is simply no reason for me to use 1GB of swapspace! Besides which RAM is *much* faster than swap, easier to upgrade, and just stupidly cheap. I only spent 40 on 512MB (that's probably expensive now), & don't expect to upgrade anytime soon.......
Hmmm, I think this is the thread on linux kernel mailing list that covers it more in depth http://www.uwsg.iu.edu/hypermail/linux/kernel/0101.3/1221.html but don't have time to read all of it... there is a comment somewhere in there though that shows that Linus should shoot himself though.
Adam
Get your FREE download of MSN Explorer at http://explorer.msn.com/intl.asp
main@lists.alug.org.uk http://www.anglian.lug.org.uk/ http://lists.alug.org.uk/mailman/listinfo/main Unsubscribe? See message headers or the web site above!