Kaushal Shriyan <kaushalshriyan at gmail.com> wrote: > I have loaded CentOS 5.6 on HP DL 180G6 2U Rack Server and the > physical RAM is 32 GB. As per > http://www.centos.org/docs/5/html/Deployment_Guide-en-US/ch-swapspace.html > It says it should be 1 x of Physical RAM or less. Not sure about the > "less" word in deciding swap space size IIRC, the traditional rationale behind having at least as much swap space as physical memory has to do with being able to save a core file (on reboot) if the kernel bites it. Different UNIX variants had slightly different concerns and values (in some cases 2x physical memory). Other things that can influence wanting a lot of swap are: - if you need to support hibernation - if you're using kexec (I think) - if you're using tmpfs filesystems to any degree - if you're using a serious amount of buffer cache (such as on a file server) In all of those cases, swap will generally be used in a sensible fashion; you may use a lot, but that doesn't imply thrashing. Without those circumstances, you still want a reasonable amount, but I'd be less concerned with matching the amount of physical RAM. The rule of thumb I use to start on CentOS systems is a minimum of 2G total or 1G per core, whichever is greater. Despite that, if your swap in/out parameters are consistently non-zero, you're best to solve it with RAM. If you put your swap on an LVM volume, you can always easily tune it up and down as your needs change. Devin -- If you have any trouble sounding condescending, consult a UNIX user.