On Jul 19, 2010, at 2:38 PM, Horace Demmink wrote: > 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?
Yes. In the local dd case, you will be testing the memory bandwidth, too. > 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. There are many, many, many different ways to configure, create load, and measure performance. Perhaps you can start with explaining how you did those things. -- richard -- Richard Elling rich...@nexenta.com +1-760-896-4422 Enterprise class storage for everyone www.nexenta.com _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
