mpt(4) enabling write cache on raw disk
kickbsd at yandex.com
Mon Jul 30 15:19:18 UTC 2012
29.07.2012, 17:00, "Stefan Johansson" <steve.johansson at telia.com>:
> I have a HP 3080X SAS/SATA 8 port mpt(4) controller card that I want to use in
> a ZFS setup.
> My problem is that the write cache is not enabled on disks that are not a part of a RAID volume (RAID0 or RAID1).
> The write speed is limited to about 20MB/s with both UFS and ZFS.
> If I create a RAID0 volume with mptutil(8) and then destroy it, write cache gets enabled and the write speed reaches about 60MB/s with UFS and ZFS.
> Unfortunately it won't survive a reboot.
> Has anyone else seen this problem with mpt(4) controllers and/or knows how to fix it?
I have to create 8 raid0 volumes consisting of one drive, and then enable
#/usr/sbin/mptutil volume cache 0 enable
#/usr/sbin/mptutil volume cache 1 enable
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