Hello, I'm working on building a iSCSI storage server to use as the backend for virtual servers. I am far more familiar with FreeBSD and Linux, but want to use OpenSolaris for this project because of Comstar & ZFS. My plan was to have a 24 2TB Hitachi SATA drives connected via SAS expanders to two OpenSolaris servers working in a fallover setup. These servers would provide iSCSI shares the the virtual hosting servers over a 10Gb infiniband connection.
At this point I'm having trouble getting the performance I was expecting out of ZFS. I can get between 100-130MB/s sequential read and write from my drives individually using dd. And I can maintain those speeds up to a point reading and writing to them in parallel to where I can get about 1GB/s raw to the drives until the bus becomes a bottleneck. However, when I create a zpool, either striped, raidz, or raidz2, my sequential write speeds end up around the write speed of a single drive. I wasn't expecting this, using the same hardware running linux and an md-raid/lvm2 setup I can easily achieve 1100MB/s+ sequential reads and 600MB/s+ sequential writes. Shouldn't I, in theory, be able to achieve similar results with zfs? I'm at a loss where to go from here to troubleshoot and tune this setup, or if I have unreasonable expectations of the performance I should be able to achieve. If anyone could offer insight or advice, I'd greatly appreciate it. -- Horace Demmink RackSphere Inc. _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
