On Thu, 29 Jan 2009, Richard Tector wrote:
Charles Sprickman wrote:
Hello,
I think this needs a few more eyes:
http://lists.freebsd.org/pipermail/freebsd-scsi/2009-January/003782.html
In short, writes are slow, likely do to the write-cache being enabled on
the controller. The sysctl used in 6.x to turn the cache off don't seem to
be in 7.x.
I have two Dell 860's here also running 7.1-REL.
A simple dd on one shows roughly 60MB/s writes to a mirror of 2 320GB disks
on what I'm assuming is the same LSI controller card (SAS5)
rich...@moses:~# cat /boot/loader.conf
hw.mpt.enable_sata_wc=1
Seems to work just fine for me.
Well, now I'm puzzled. A "sysctl -a" shows no "hw.mpt." tree at all:
# sysctl -a|grep hw.mpt
#
It's a poor test, but:
# dd if=/dev/zero of=/jails/foo count=1M
1048576+0 records in
1048576+0 records out
536870912 bytes transferred in 144.830977 secs (3706879 bytes/sec)
# dd if=/jails/foo of=/dev/null
1048576+0 records in
1048576+0 records out
536870912 bytes transferred in 4.136582 secs (129786112 bytes/sec)
I added the tunable to loader.conf:
$ cat /boot/loader.conf
hw.mpt.enable_sata_wc=1
And still nothing in the sysctl output (there was on 6.4 on this same
hardware, FWIW):
$ sysctl -a |grep hw.mpt
$
However, performance did improve:
# dd if=/dev/zero of=/jails/foo count=16M
16777216+0 records in
16777216+0 records out
8589934592 bytes transferred in 276.332753 secs (31085474 bytes/sec)
Any idea what happened to the sysctl? Is there some other method to
verify the loader tunable took (other than testing the throughput)?
I assume there's still no management tools for these controllers, right?
Thanks,
Charles
Regards,
Richard
_______________________________________________
freebsd-stable@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-stable
To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
