> On July 14, 2008 7:49:58 PM -0500 Bob Friesenhahn > <[EMAIL PROTECTED]> wrote: > > With ZFS and modern CPUs, the parity calculation is > surely in the noise to the point of being unmeasurable. > > I would agree with that. The parity calculation has *never* been a > factor in and of itself. The problem is having to read the rest of > the stripe and then having to wait for a disk revolution before writing. > -frank
And this is where a HW RAID controller comes in. We hope it has a uP for the calculations, full knowledge of the head positions, and a list of free blocks -- then it simply chooses one of the drives that suit the criteria for the RAID level used and writes immediately to the free block under one of the heads. If only ... Maybe in a few years Sun will make a HW RAID controller using ZFS once we all get the bugs out. With Flash updates this should work wonderfully. This message posted from opensolaris.org _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
