Ooops, didn't put out the particulars of the system. This is a
FreeBSD 8.0 system that has not been updated.
We upped the block size of the da driver, not MAXPHYS. I'll give that
a shot.
Thanks.
On 09/28/2010 01:45 AM, Alexander Motin wrote:
Stephen Sanders wrote:
I'm trying a disk throughput experiment where in two 3ware raid 6's are
being put into a g_strip raid 0.
The raid 6's are using 8 7200RPM disks. The disk transfer rate is
~80MB/s. Using a load generation tool that is using O_DIRECT for I/O,
I've generated the following short output from iostat. Needless to say,
the write performance is a lot less than I'm expecting.
We've modified the kernel such that our KB/t figure is closer to 512KB/t
per disk when measured without the g_strip. With g_strip turned on, the
KB/t number is more like 60KB/t.
The question is how do I get g_stripe to write larger transactions to
the disk ?
How old is your system? There was bug, fixed 8-12 months ago, making
fast mode in gstripe not working on systems with increased MAXPHYS. As I
understand, it is what you've changed in your kernel.
_______________________________________________
[email protected] mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-performance
To unsubscribe, send any mail to "[email protected]"
