On Mar 9, 2010, at 6:13 PM, Damon Atkins wrote: > Sorry, Full Stripe on a RaidZ is the recordsize ie if the record size is 128k > on a RaidZ and its made up of 5 disks, then 128k is spread across 4 disks > with the calc parity on the 5 disk, which means the writes are 32k to each > disk.
Nominally. > For a RaidZ, when data is written to a disk, are individual 32k join together > to the same disk and written out as a single I/O to the disk? I/Os can be coalesced, but there is no restriction as to what can be coalesced. In other words, subsequent writes can also be coalesced if they are contiguous. > e.g. 128k for file a, 128k for file b, 128k for file c. When written out > does zfs do > 32k+32k+32k i/o to each disk, or will it do one 96k i/o if the space is > available sequentially? I'm not sure how one could write one 96KB physical I/O to three different disks? -- richard ZFS storage and performance consulting at http://www.RichardElling.com ZFS training on deduplication, NexentaStor, and NAS performance http://nexenta-atlanta.eventbrite.com (March 16-18, 2010) _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
