----- Цитат от Andrea Suisani (sick...@opinioni.net), на 28.02.2012 в 09:54 -----
> On 02/28/2012 04:52 AM, Rob Wultsch wrote: >> On Wed, Feb 22, 2012 at 2:31 PM, james<ja...@mansionfamily.plus.com> wrote: >>> Has anyone considered managing a system like the DragonFLY swapcache for a >>> DBMS like PostgreSQL? >>> >> >> https://www.facebook.com/note.php?note_id=388112370932 >> > > in the same vein: > > http://bcache.evilpiepirate.org/ > > from the main page: > > "Bcache is a patch for the Linux kernel to use SSDs to cache other block > devices. It's analogous to L2Arc for ZFS, > but Bcache also does writeback caching, and it's filesystem agnostic. It's > designed to be switched on with a minimum > of effort, and to work well without configuration on any setup. By default it > won't cache sequential IO, just the random > reads and writes that SSDs excel at. It's meant to be suitable for desktops, > servers, high end storage arrays, and perhaps > even embedded." > > it was submitted to linux kernel mailing list a bunch of time, the last one: > > https://lkml.org/lkml/2011/9/10/13 > > > Andrea > I am successfully using facebook's flashchache in write-through mode - so it speeds only reads. I have seen 3 times increase on TPS for databases that do not fit in RAM. I am using Intel X-25E over RAID10 of 4 SAS disks. I have tested also writeback mode but the gain is not so huge and there is a considerable risk for loosing all your data if/when the SSD fails. Best regards -- Luben Karavelov
