[EMAIL PROTECTED] wrote: > > measurable benefits for caching local disks as well? NAND-flash SSD > > I'm confused, the only reason I can think of making a > > To create a pool with cache devices, specify a "cache" vdev > with any number of devices. For example: > > # zpool create pool c0d0 c1d0 cache c2d0 c3d0 > > Cache devices cannot be mirrored or part of a raidz confi- > guration. If a read error is encountered on a cache device, > that read I/O is reissued to the original storage pool dev- > ice, which might be part of a mirrored or raidz > configuration. > > The content of the cache devices is considered volatile, as > is the case with other system caches. > > device non-volatile was to fill the ARC after reboot, and the in ram > ARC pointers for the cache device will take quite abit of ram too, so > perhaps spending the $$ on more system ram rather than a SSD cache > device would be better? unless you have really slow iscsi vdevs :-) >
Consider a case where you might use large, slow SATA drives (1 TByte, 7,200 rpm) for the main storage, and a single small, fast (36 GByte, 15krpm) drive for the L2ARC. This might provide a reasonable cost/performance trade-off. -- richard _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
