Thank you for you responses, first of all I need same amount of swap space as of memory, because I want to use hibernation. Problem of placing swap partition on SSD is not with too many writes, but with to much space used for nothing (in my case 8 GB, 16 GB in not so far future). I know about "swappiness" kernel tunable, but I guess it has nothing to do with how often is partition "simply touched for nothing" and therefore hard drive is spinned up. For example - if I set HDD to spin down after two minutes and kernel will touch swap approximately every five minutes, it means that hard drive will be spinned up 120 times every day (10 hours of power on), 43 800 cycles per year which will definitely wreck my HDD :-(. 2013/7/23 Jorge Fábregas <jorge.fabregas at gmail.com> > On 07/23/2013 01:22 PM, Martin Šťastný wrote: > > how often is kernel touching swap space > > There's a kernel tunable called "swappiness" [1] to control that. You > can add an entry in /etc/sysctl.conf like this: > > vm.swappiness=0 > > ...and the kernel will avoid, as much as it can, to use swap. > > HTH, > Jorge > > [1]: http://en.wikipedia.org/wiki/Swappiness > _______________________________________________ > CentOS mailing list > CentOS at centos.org > http://lists.centos.org/mailman/listinfo/centos >