178 lines
6.6 KiB
Plaintext
178 lines
6.6 KiB
Plaintext
.\" Copyright (c) 1983 The Regents of the University of California.
|
|
.\" All rights reserved.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\" 3. All advertising materials mentioning features or use of this software
|
|
.\" must display the following acknowledgement:
|
|
.\" This product includes software developed by the University of
|
|
.\" California, Berkeley and its contributors.
|
|
.\" 4. Neither the name of the University nor the names of its contributors
|
|
.\" may be used to endorse or promote products derived from this software
|
|
.\" without specific prior written permission.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
.\" SUCH DAMAGE.
|
|
.\"
|
|
.\" @(#)equip.ms 6.2 (Berkeley) 4/16/91
|
|
.\"
|
|
.ds RH Equipment
|
|
.NH
|
|
Equipment
|
|
.PP
|
|
Various combinations of the three manufacturers disk controllers,
|
|
and two pairs of Winchester disk drives were tested on both
|
|
VAX 11/780 and VAX 11/750 CPUs. The Emulex and Systems Industries
|
|
disk controllers were interfaced to Fujitsu 2351A
|
|
``Eagle''
|
|
404 Megabyte disk drives.
|
|
The DEC UDA50 disk controller was interfaced to two DEC RA81
|
|
456 Megabyte Winchester disk drives.
|
|
All three controllers were tested on the VAX 780 although
|
|
only the Emulex and DEC controllers were benchmarked on the VAX 11/750.
|
|
Systems Industries makes a VAX 11/750 CMI interface for
|
|
their controller, but we did not have time to test this device.
|
|
In addition, not all the storage systems were tested for
|
|
two drive throughput.
|
|
Each of the controllers and disk drives used in the benchmarks
|
|
is described briefly below.
|
|
.NH 2
|
|
DEC UDA50 disk controller
|
|
.PP
|
|
This is a new controller design which is part of a larger, long range
|
|
storage architecture referred to as
|
|
``DSA''
|
|
or \fBD\fRigital \fBS\fRtorage \fBA\fRrchetecture.
|
|
An important aspect of DSA is migrating a large part
|
|
of the storage management previously handled in the operating
|
|
system to the storage system. Thus, the UDA50 is a much more
|
|
intelligent controller than previous interfaces like the RH750 or
|
|
RH780.
|
|
The UDA50 handles all error correction.
|
|
It also deals with most of the physical storage parameters.
|
|
Typically, system software requests a logical block or
|
|
sequence of blocks.
|
|
The physical locations of these blocks,
|
|
their head, track, and cylinder indices,
|
|
are determined by the controller.
|
|
The UDA50 also orders disk requests to maximize throughput
|
|
where possible, minimizing total seek and rotational delays.
|
|
Where multiple drives are attached to a single controller,
|
|
the UDA50 can interleave
|
|
simultaneous
|
|
data transfers from multiple drives.
|
|
.PP
|
|
The UDA50 is a UNIBUS implementation of a DSA controller.
|
|
It contains 52 sectors of internal buffering to minimize
|
|
the effects of a slow UNIBUS such as the one on the VAX-11/780.
|
|
This buffering also minimizes the effects of contention with
|
|
other UNIBUS peripherals.
|
|
.NH 2
|
|
Emulex SC750/SC780 disk controllers
|
|
.PP
|
|
These two models of the same controller interface to the CMI bus
|
|
of a VAX 11/750 and the SBI bus of a 11/VAX 780, respectively.
|
|
To the operating system, they emulate either an RH750 or
|
|
and RH780.
|
|
The controllers install in the
|
|
MASSBUS
|
|
locations in the CPU cabinets and operate from the
|
|
VAX power suplies.
|
|
They provide an
|
|
``SMD''
|
|
or \fBS\fRtorage \fBM\fRodule \fBD\fRrive
|
|
interface to the disk drives.
|
|
Although a large number of disk drives use this interface, we tested
|
|
the controller exclusively connected to Fujitsu 2351A disks.
|
|
.PP
|
|
The controller ws first implemented for the VAX-11/750 as the SC750
|
|
model several years ago. Although the SC780 was introduced more
|
|
recently, both are stable products with no bugs known to us.
|
|
.NH 2
|
|
System Industries 9900 disk controller
|
|
.PP
|
|
This controller is an evolution of the S.I. 9400 first introduced
|
|
as a UNIBUS SMD interface.
|
|
The 9900 has been enhanced to include an interface to the VAX 11/780 native
|
|
bus, the SBI.
|
|
It has also been upgraded to operate with higher data rate drives such
|
|
as the Fujitsu 2351As we used in this test.
|
|
The controller is contained in its own rack-mounted drawer with an integral
|
|
power supply.
|
|
The interface to the SMD is a four module set which mounts in a
|
|
CPU cabinet slot normally occupied by an RH780.
|
|
The SBI interface derives power from the VAX CPU cabinet power
|
|
supplies.
|
|
.NH 2
|
|
DEC RA81 disk drives
|
|
.PP
|
|
The RA81 is a rack-mountable 456 Megabyte (formatted) Winchester
|
|
disk drive manufactured by DEC.
|
|
It includes a great deal of technology which is an integral part
|
|
of the DEC \fBDSA\fR scheme.
|
|
The novel technology includes a serial packet based communications
|
|
protocol with the controller over a pair of mini-coaxial cables.
|
|
The physical characteristics of the RA81 are shown in the
|
|
table below:
|
|
.DS
|
|
.TS
|
|
box,center;
|
|
c s
|
|
l l.
|
|
DEC RA81 Disk Drive Characteristics
|
|
_
|
|
Peak Transfer Rate 2.2 Mbytes/sec.
|
|
Rotational Speed 3,600 RPM
|
|
Data Sectors/Track 51
|
|
Logical Cylinders 1,248
|
|
Logical Data Heads 14
|
|
Data Capacity 456 Mbytes
|
|
Minimum Seek Time 6 milliseconds
|
|
Average Seek Time 28 milliseconds
|
|
Maximum Seek Time 52 milliseconds
|
|
.TE
|
|
.DE
|
|
.NH 2
|
|
Fujitsu 2351A disk drives
|
|
.PP
|
|
The Fujitsu 2351A disk drive is a Winchester disk drive
|
|
with an SMD controller interface.
|
|
Fujitsu has developed a very good reputation for
|
|
reliable storage products over the last several years.
|
|
The 2351A has the following physical characteristics:
|
|
.DS
|
|
.TS
|
|
box,center;
|
|
c s
|
|
l l.
|
|
Fujitsu 2351A Disk Drive Characteristics
|
|
_
|
|
Peak Transfer Rate 1.859 Mbytes/sec.
|
|
Rotational Speed 3,961 RPM
|
|
Data Sectors/Track 48
|
|
Cylinders 842
|
|
Data Heads 20
|
|
Data Capacity 404 Mbytes
|
|
Minimum Seek Time 5 milliseconds
|
|
Average Seek Time 18 milliseconds
|
|
Maximum Seek Time 35 milliseconds
|
|
.TE
|
|
.DE
|
|
.ds RH Methodology
|
|
.bp
|