Bob Friesenhahn wrote: > Can someone please describe to me the actual underlying I/O operations > which occur when a 128K block of data is written to a storage pool > configured as shown below (with default ZFS block sizes)? I am > particularly interested in the degree of "striping" across mirrors > which occurs. This would be for Solaris 10 U4. >
My observation, is that each metaslab is, by default, 1 MByte in size. Each top-level vdev is allocated by metaslabs. ZFS tries to allocate a top-level vdev's metaslab before moving onto another one. So you should see eight 128kByte allocs per top-level vdev before the next top-level vdev is allocated. That said, the actual iops are sent in parallel. So it is not unusual to see many, most, or all of the top-level vdevs concurrently busy. Does this match your experience? -- richard > > NAME STATE READ WRITE CKSUM > Sun_2540 ONLINE 0 0 0 > mirror ONLINE 0 0 0 > c4t600A0B80003A8A0B0000096A47B4559Ed0 ONLINE 0 0 0 > c4t600A0B800039C9B500000AA047B4529Bd0 ONLINE 0 0 0 > mirror ONLINE 0 0 0 > c4t600A0B80003A8A0B0000096E47B456DAd0 ONLINE 0 0 0 > c4t600A0B800039C9B500000AA447B4544Fd0 ONLINE 0 0 0 > mirror ONLINE 0 0 0 > c4t600A0B80003A8A0B0000096147B451BEd0 ONLINE 0 0 0 > c4t600A0B800039C9B500000AA847B45605d0 ONLINE 0 0 0 > mirror ONLINE 0 0 0 > c4t600A0B80003A8A0B0000096647B453CEd0 ONLINE 0 0 0 > c4t600A0B800039C9B500000AAC47B45739d0 ONLINE 0 0 0 > mirror ONLINE 0 0 0 > c4t600A0B80003A8A0B0000097347B457D4d0 ONLINE 0 0 0 > c4t600A0B800039C9B500000AB047B457ADd0 ONLINE 0 0 0 > mirror ONLINE 0 0 0 > c4t600A0B800039C9B500000A9C47B4522Dd0 ONLINE 0 0 0 > c4t600A0B800039C9B500000AB447B4595Fd0 ONLINE 0 0 0 > > > Thanks, > > Bob > ====================================== > Bob Friesenhahn > [EMAIL PROTECTED], http://www.simplesystems.org/users/bfriesen/ > GraphicsMagick Maintainer, http://www.GraphicsMagick.org/ > > _______________________________________________ > zfs-discuss mailing list > zfs-discuss@opensolaris.org > http://mail.opensolaris.org/mailman/listinfo/zfs-discuss > _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
