From owner-freebsd-bugs  Thu Jun  8 11:30: 7 2000
Delivered-To: freebsd-bugs@freebsd.org
Received: from freefall.freebsd.org (freefall.FreeBSD.ORG [204.216.27.21])
	by hub.freebsd.org (Postfix) with ESMTP id F37EC37BC69
	for <freebsd-bugs@FreeBSD.org>; Thu,  8 Jun 2000 11:30:00 -0700 (PDT)
	(envelope-from gnats@FreeBSD.org)
Received: (from gnats@localhost)
	by freefall.freebsd.org (8.9.3/8.9.2) id LAA99542;
	Thu, 8 Jun 2000 11:30:00 -0700 (PDT)
	(envelope-from gnats@FreeBSD.org)
Received: by hub.freebsd.org (Postfix, from userid 32767)
	id 640E337BB68; Thu,  8 Jun 2000 11:20:53 -0700 (PDT)
Message-Id: <20000608182053.640E337BB68@hub.freebsd.org>
Date: Thu,  8 Jun 2000 11:20:53 -0700 (PDT)
From: cwilkes@singingfish.com
To: freebsd-gnats-submit@FreeBSD.org
X-Send-Pr-Version: www-1.0
Subject: misc/19129: AMI Raid Express 200 card extremely slow ( < 6MB/s)
Sender: owner-freebsd-bugs@FreeBSD.ORG
Precedence: bulk
X-Loop: FreeBSD.org


>Number:         19129
>Category:       misc
>Synopsis:       AMI Raid Express 200 card extremely slow ( < 6MB/s)
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Thu Jun 08 11:30:00 PDT 2000
>Closed-Date:
>Last-Modified:
>Originator:     Chris Wilkes
>Release:        4.0
>Organization:
>Environment:
FreeBSD octopus 4.0-STABLE FreeBSD 4.0-STABLE #0: Sun May 28 11:04:59 GMT 2000
>Description:
File server with an AMI MegaRaid Express 200 card attached to a disk enclosure
with 8 9G LVD SCSI2 drives, for a total of ~60G of RAID5 storage.
Disk writes are extremely slow on it, around 6MB/s.  Called AMI and they
suggested moving from Linux to FreeBSD.  Did that and I still see the same
(bad) performance.
Speed (MB/s)	Description
17.1		internal SCSI -> other internal SCSI
16.5		raid -> internal scsi
6.05		internal scsi -> raid
4.10		raid -> raid

The drives are rated at 20MB/s, I'm really happy with the 17.1MB/s I'm seeing
for local to local.  I was expecting a huge gain up to about the 80MB/s max
spec for scsi-2, but instead writes are 1/3 the speed.
>How-To-Repeat:
Reformated drives after the system became unstable and core dumped on an
fsck.  Still the same performance numbers.
>Fix:


>Release-Note:
>Audit-Trail:
>Unformatted:


To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-bugs" in the body of the message