Hi, I just installed OpenSolaris on my Dell Optiplex 755 and created raidz2 with a few slices on a single disk. I was expecting a good read/write performance but I got the speed of 12-15MBps. How can I enhance the read/write performance of my raid? Thanks, Abhi.
Abhishek Gupta wrote:> Hi, > > I just installed OpenSolaris on my Dell Optiplex 755 and created > raidz2 with a few slices on a single disk. I was expecting a good > read/write performance but I got the speed of 12-15MBps. > How can I enhance the read/write performance of my raid? > Thanks, > Abhi.You absolutely DON''T want to do what you''ve done. Creating a ZFS pool (or, for that matter, any RAID device,whether hardware or software) out of slices/partitions of a single disk is a recipe for horrible performance. In essence, you reduce your performance to 1/N (or worse) of the whole disk, where N is the number of slices you created. So, create your zpool using disks or partitions from different disks. It''s OK to have more than one partition on a disk - just use them in different pools for reasonable performance. -- Erik Trimble Java System Support Mailstop: usca22-123 Phone: x17195 Santa Clara, CA Timezone: US/Pacific (GMT-0800)
On Mon, May 10 at 9:08, Erik Trimble wrote:>Abhishek Gupta wrote: >>Hi, >> >>I just installed OpenSolaris on my Dell Optiplex 755 and created >>raidz2 with a few slices on a single disk. I was expecting a good >>read/write performance but I got the speed of 12-15MBps. >>How can I enhance the read/write performance of my raid? >>Thanks, >>Abhi. > >You absolutely DON''T want to do what you''ve done. Creating a ZFS >pool (or, for that matter, any RAID device,whether hardware or >software) out of slices/partitions of a single disk is a recipe for >horrible performance. > >In essence, you reduce your performance to 1/N (or worse) of the >whole disk, where N is the number of slices you created.+1 raidz2 on a single device is the opposite of what you want to do. If you need some improvement in bitrot recovery you can enable multiple copies on a single disk, which may help, but for any of the raidz variants, you really need to use multiple physical devices to provide that capability. --eric -- Eric D. Mudama edmudama at mail.bounceswoosh.org