On Sat, Dec 8, 2012 at 8:49 PM, Fabio Pedretti <fabio....@libero.it> wrote: > 1. Traditional swap on hard drive is still used and suggested, zram is a > better alternative and a complement to it, so it may for sure be useful to > everyone who actually use swap on hard drive.
I am not sure that zram makes good use of a harddrive as backing swap. My personal experience has been that either 1) Zram is enough, and there is no need to use HDD as swap; or 2) Once Zram is filled, the newer and more frequently used pages get written to HDD, and the memory used by the stale pages in Zram means that the system is slower that it would be without zram; or 3) Zram is usually enough but occasionally a misbehaving process will attempt to allocate all memory. Disabling the large on disk swap means that the bad process is OOM killed before it leaves the system unusable due to swap death. As I understand smart use of harddisk as a backing store and trim support is not currently supported, as the currently focus is keeping compcache small simple and obviously correct so it can leave staging, and work will not begin on adding such features till after 3.8 [1] . After 3.8 these performance problems may be fixed, and zram may make effective use on an on disk backing store. As it stands, I use compcache by itself without any on disk swap. Clearly on disk swap would be required for hibernate though. [1] http://code.google.com/p/compcache/issues/detail?id=98 -- John C. McCabe-Dansted -- Ubuntu-devel-discuss mailing list Ubuntu-devel-discuss@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-devel-discuss
