On Feb 8, 2009, at 16:12, Vincent Fox wrote: > Do you think having log on a 15K RPM drive with the main pool > composed of 10K RPM drives will show worthwhile improvements? Or am > I chasing a few percentage points?
Another important question is whether it would be sufficient to purchase only one 15K disk, or should two be purchased and they be mirrored? What would happen if the device that the ZIL lives on suddenly goes away or start returning checksum errors? While an SSD is theoretically less likely to fail in some respects (no mechanical parts), what happens if it fails? How important is mirroring on log devices? Another question comes to mind: if you have multiple pools, can they all share one log device? For example, if you have twelve disks in a JBOD, and assign disks 1-4 are in mypool0, disks 4-8 are in mypool1, and disks 9-12 are in mypool2. Can you then have one SSD that can be allocated as the log device for all the pools? _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
