Jesus Cea wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > Robin Guo wrote: > | At least, s10u6 will contain L2ARC cache, ZFS as root filesystem, etc.. > > Any detail about this L2ARC thing?. I see some references in Google (a > cache device) but no "in deep" description. > > Sure. The concept is quite simple, really. We observe that solid state memories can be very fast, when compared to spinning rust (disk) drives. The Adaptive Replacement Cache (ARC) uses main memory as a read cache. But sometimes people want high performance, but don't want to spend money on main memory. So, the Level-2 ARC can be placed on a block device, such as a fast [solid state] disk which may even be volatile. This may be very useful for those cases where the actual drive is located far away in time (eg across the internet) but near-by, fast "disks" are readily available. Since the L2ARC is only a read cache, it doesn't have to be nonvolatile. This opens up some interesting possibilities for some applications which have large data stored (>> RAM) where you might get some significant performance improvements with local, fast devices.
The PSARC case materials go into some detail: http://opensolaris.org/os/community/arc/caselog/2007/618/ -- richard _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
