jak@interlan.Interlan.COM (Jeff Koehler) (05/31/91)
Subject: DN3k/4k add-on disks: solution! (long)
All information I have received from HP/Apollo and Mentor is
that YOU CANNOT ADD SCSI DISKS and access them transparently.
---------------====------ (applies to DN3500/DN4000 only)
Here is a method of adding EDSI disks.
Caution: This posting is in no way connected to HP/Apollo,
Mentor Graphics, or any service organization involved
with these companies. The suggestions embodied herein
are also not in any way supported by the author,
although the methodology has provided an add-on 780
MByte disk that has been running smoothly for weeks.
Abstract: I have seen enough of the questions about how
to add disks to HP/Apollo DN3500/4000 nodes; it
is time to lay the rumors to rest. Sorry, this only
covers these two models.
To add EDSI disks, and you must add them
externally, since there is no room in the original
chassis for additional (full height) drives. This
article describes how I added an external 760 MB
disk subsystem to a DN3500. It applies equally well
to 380 MB drives, and/or DN4000's, with minor changes.
The HP/Apollo Multiple Disk Expansion Module (MDEM)
manual is referenced heavily throughout this article.
It is strongly suggested you order it before you attempt
to install your own, HP/Apollo's, or Mentor's expansion
modules. Ordering instructions for this manual are
included in this article. The manual specifies you must
have the following revisions of software to operate the
subsystem(s) (page 1-3):
SR9.7.1 and media type SFW-PSK3-MED9
SR10.1 and media type SFW-PSK4-MED10
My SR10.1 installation needed no additional patches.
---->>> Note: you must add a disk of the same size as the
existing internal disk. (380 & 380, 760 & 760).
You may mix Micropolis and Maxtors, but both must
be of the `fast actuator' type. The disks must
be EDSI, and are controlled from the EDSI ports
of the WD7000 controller (required).
---->>> While SCSI disks may be electrically compatible with
these machines, I was unable to describe their existence
to Domain/OS, which pretty much renders them useless.
You can, however, add 8mm and 1/4 inch tape drives on
the WD7000 SCSI port (the manual covers this, too).
----- ----- ----- ----- ----- ----- ----- ----- ----- ----- -----
This article may contain dated material. It was first released
on May 30, 1991 to the Internet News group `comp.sys.apollo'
by J.A.Koehler. It is hereby released to the public domain.
================================================================
Introduction and Background ... part 1
================================================================
I am posting this in response to the apparent lack of technical
information available from Mentor and HP when attempting to
increase the disk capacity of an HP/Apollo DN4000 or DN3500.
It appears they felt that the fewer technical details they released,
the more pre-disposed you would be toward buying their turnkey disk
subsystems, at what I consider inflated rates. To illustrate,
compare the confustion in this News group to adding a second disk
to an IBM PC compatible -- that information is pretty much
considered public knowledge. Most of the information was construed
from HP/Apollo and Mentor manuals and service people, and this
compendium is intended to save the general public from spending days
on the phone chasing down all of the loose ends.
I have added a 760 MB Maxtor to my DN3500 and it has passed SAX
and all of my ad hoc regression tests. The cost was approximately
1/4 of the retail price (see below for more on costs). A word of
caution: I have only been running this configuation for about 3
weeks now. My primary use for it is vendor libraries and software,
so if it does fail, my data loss isn't irreversible, only irritating.
Apply appropriate scrutiny to the level of confidence you will
entrust upon my `suggestions'.
If you are at all interested in performing this yourself, save
this article in a file (with the command 's file') and print it.
Please DO NOT expect me to support your add-on modules in any
manner -- I am just as busy as you are. If you are NOT a brave and
daring hardware hacker, buy the expansion module from Mentor or
HP -- my method will probably take up a considerable amount of
your valuable time.
Estimated costs (760 MB, 650 MB formatted)
-----------------------------------------------------
$10,000 un-official Mentor price (not quoted)
$ 2,675 piece-parts price, plus $100 for chassis
$ 2,115 if you use non-HP cables and `find' a chassis
-----------------------------------------------------
For those of you on a shoe-string budget, that $2,100 price tag
looks pretty appealing. The relative price of adding the third
and fourth disks may be less attractive, for you must purchase
a second WD7000 controller card in addition to the other parts.
I decided it would be more cost effective to resort to this only
after all of our nodes has a second external disk installed.
----- ----- -----
The important issues to remember are:
Why external? There isn't room to add another disk inside
the chassis. An external subsystem requires
shielded cable, etc. for EMI reasons (and the
fact that users may walk on the cable!)
DN3500: If you already have a WD7000 controller, I think
you are all set. If you don't, I am not sure what
rev you need to support it. You should probably
call HP regardless, to determine whether it is
possible with your configuration.
DN4000: My customer service rep said you need rev 25 or
later on your motherboard. You probably DON'T have
this on your DN4000, and it costs a few thousand
to have Mentor upgrade it. I avoided this situation
by adding it to our DN3500 instead. Again, you
should contact HP or Mentor to check on the
compatability with your particular configuration.
IMPORTANT: 1) You must add an external disk OF THE SAME SIZE as
the internal one. This applies to any of these
configurations.
2) You must have a Western Digital 7000v SCSI/EDSI
controller. Note: WD customer service claims this
is a special OEM version of the 7000 (hence the 'v').
I was lead to understand that the non-OEM version
doesn't support both SCSI and EDSI, and the tech-
nician on WD's customer service line was unsure of
the actual differences. If your machine came with
one, its probably the right one. If you are trying
to add a second controller, Better call HP to be sure
you get the correct model.
3) You need NOT purchase a second controller to add 1
external drive. You MUST purchase a second con-
troller to add a third and fourth drive.
4) You must use the fast-actuator drive types (either
Micropolis or Maxtor). The trailing 'E' on a Maxtor
indicates a fast actuator drive; I am not sure of
the Part number for the Micropolis, but you can check
on the internal one in your DNxx00 for an example.
As long as they are the same capacity, you may mix the
Micropolis and Maxtor drives on the same controller.
also: You may use the SCSI bus to add a 1/4 tape drive
or an 8mm tape drive. The manual describes these
in detail, too (but I don't -- I haven't tried it).
For those of you that are serious about this, I whole-heartedly sug-
gust you order the manual and take a look for yourself. Be sure to
get a quote from HP or Mentor to justify the cost savings involved,
since you will have to remind yourself it was worth the savings to
not buy the `turnkey' alternative.
Here is the manual number:
D-16411-0 manual For Multiple Disk Expansion
Module (MDEM or DEM).
(obsolete Apollo number 016411-A00)
The cost is $6.00; minimum order is $20.00; so find something else
you were going to order from them or you'll end up overpaying.
This is a SPECIAL ORDER item and is available from your local
ORDER PROCESSING DESK. Contact your HP sales rep to find the
location of the order processing desk nearest you. HP spare
parts will be unable to help you out on this item.
The manual gives you the complete installation instructions
with the exception of how to INVOL and MOUNT it (some hints are
provided in part 4 of this article).
================================================================
What I have learned ... part 2
================================================================
Now, let's discuss what ISN'T covered in the manual -- the Disk
Expansion Module itself (after all, you are saving a bundle, you
must be prepared to provide some elbow grease). If you are familiar
with the industry standard method of configuring MFM, RLL and EDSI
disks, you are almost there. The secret lies in the 'shared' control
(at least I think they are control) lines:
WD7000 controller +----------------+
+------------+ /========> ESDI drive 0 |
| | drive 0 || | (internal) |
| 20 pin ==============/ +----||----------+
| | ||
| | +---+ || unshared 34 pin cable
| | shared | | ||
| 34 pin ===================| |====/
| | drive 1 |PCB|
| 20 pin ===================| |--\ 80 pin external
| | | | |=====================
+------------+ | |--/ (12837-001)
+---+
012824
The 80 pin external cable will go to the external chassis and
mate with another 'PCB' (012824) WHICH YOU WILL INSTALL. This
'PCB' has no active components, but provides a neat and easy
method of interconnecting the 80 pin shielded external cable to
both chassis. It is debatable whether the PCB is worth the
$140, but unless you intend to produce your own PCBs, you are
left with little choice. I'm sure both EMI and connection
integrity were of major concern when designing this interface,
and this PCB provides a sturdy segue from external to internal
cabling.
It is probably worth mentioning here that the screws and brackets
itemized in the parts list are well worth the money. If you are
truly a `Scrooge', then buy 1 bracket and manufacture the rest, using
it as a template (they are really just PC-type brackets with a
mounting hole machined specifically for the Honda connector).
The Honda connector itself is one of the best I have seen; its
locking mechanism is quite sturdy and passes my psuedo-rigorous
tests at yanking it out. You will probably appreciate its quality
more thoroughly the first time a user plays `Captain Ahab' with
your expansion cable and goes sprawling across the floor.
The external chassis end of the 80-pin shielded cable is split into
its 20-pin and 34-pin constituents using a `spare' PCB I bought
just for that purpose (perhaps my additional parts quantities will
make more sense after reading this section). I used the PCB with
another spare bracket and mounted it in my tower chassis. Since
I didn't have an official MDEM (DEM) chassis to inspect as a guide,
I used a beeping continuity tester to insure that pin 1 from the
WD7000 controller corresponded to pin 1 of the edge connector for
all of the disk cables.
+------------------------------------------
|
| +-------------+
+---+ 34 pin +--+| |
| |============| || external |
80 pin external /--| | (013046) +--+| EDSI |
==================| |PCB| | drive 1 |
(from DNxx00) \--| | 20 pin +--+| |
| |============| || (add the |
+---+ (013047) +--+| terminator!)|
| +-------------+
|
| (inside your hack-job MDEM)
+------------------------------------------
Note: I am not sure about the cable numbers, they
were taken from figure 2-16 of the manual, and
I am asssuming they will work.
The purpose of this section is to elighten you on the internals
of the cabling. If you are having trouble with these primitive
illustrations, look at the manual, figures 2-16 and 2-19.
The two cables internal to the expansion chassis are available
from HP/Apollo, by using the same cables used internal to the
DN chassis. Upon close examination, I noticed two points:
1) They have HP/Apollo part numbers on them so you
can order them from spare parts if you like.
Unfortunately, I cannot open my node right now
to confirm the part numbers for this article, but
the ones I have written down are mentioned.
2) They are essentially no different than any other
standard disk cable, except they are made of
`tubular' cable instead of `ribbon'.
I decided to make my own, but you can purchase them from any
computer supply store, too.
IMPORTANT: some PCs use a twist in the 34 pin cable,
you must NOT have a twist in yours.
You can probably find the edge and two-row header connectors
from a cheap source and make your own cables from ribbon cable.
This was my method, and since we have the items in large quantities
in local stock, my cost was only a favor.
================================================================
the compiled parts list ... Part 3
================================================================
This will only cover the case of 1 external 760 MB drive. Once
you have added it, you should be able to figure out what parts
will be needed to install a total of 3 additional drives
per DN3k/4k.
Now we get to the nitty gritty. I obtained my parts from 3 diff-
erent sources:
a) HP/Apollo misc brackets, PCB connector board,
and 3 cables
b) chassis this houses the disk(s). I managed to
'acquire' a standard tower chassis, which
is a story in itself. All you are looking
for is something with an adequate power
supply and a full height drive bay. The
external cable assembly is 10 feet long,
so you have plenty of room to hide it off
to the side, in case it is pasted with
Motley Crue stickers or something.
c) internal cables for your
own external drive
chassis: I am referring to cables you need internal
to your add-on chassis; see previous text
for more on this subject. These cables
are PROBABLY HP/Apollo numbers 013046 and
013047, but I didn't order them. See fig
2-16 of the manual for additional help.
Items b) and c) make up the equivalent of the (M)DEM mentioned
in the manual. In order to properly connect the external EDSI
cable to the disk in the DEM, you must purchase the following extra
parts when you call HP's spare parts desk:
--.-- 1 (013046 ??) Internal round 34-pin
--.-- 1 (013047 ??) Internal round 20-pin
140.00 1 012824 External PCB Board
15.00 1 012890 bracket
.10 2 014936-206 screws
The extra quantities are ALREADY INCLUDED in the Apollo parts list
that follow. I mention them here in case you happen to wonder why
my parts quantities don't correlate with those found in the manual,
pages 1-4 and 1-5.
----------------------------------------------------------------
HP/Apollo Parts for 760 MB external add-on disk:
----------------------------------------------------------------
HP Spare Parts 800-227-8164 (they take Visa!)
Tech Service Line 800-752-0900 (you must purchase support)
----------------------------------------------------------------
Cost Quan. Apollo Part No Description
------ ----- -------------- --------------------------------
140.00 2 * 012824 External PCB Board
500.00 1 $ 12837-001 80 pin external conn. cable
70.00 1 012834 20 pin internal conn. cable
90.00 1 012835 34 pin internal conn. cable
15.00 2 * 012890 bracket
.10 4 * 014936-206 screws
------ ----- -------------- --------------------------------
notes: * these items are double the normal quantity. see
previous text.
$ this is a rather expensive item, see second source mentioned
later in this section.
----------------------------------------------------------------
Parts I made myself (or available from other vendors):
----------------------------------------------------------------
1 20 pin internal connector cable
(to 20 pin edge card connector)
possibly HP/Apollo part number (013047)
1 34 pin internal connector cable
(to 34 pin edge card connector)
possibly HP/Apollo part number (013046)
1 tower PC chassis, to house the add-on drive(s).
I found the ribbon cable and connectors in our stockroom. You
will find that these are basically the same as any other EDSI,
MFM or RLL cables except Apollo didn't use ribbon. This may be
significant, but I was willing to take the chance.
I cannot be sure that my 'hack' cables are of the correct impedance,
etc., but since this EDSI configuration is terminated (at the add-on
disk end), I don't believe I am inviting any serious problems. It
doesn't appear that the HP/Apollo version are all that special.
----------------------------------------------------------------
Third party vendor for the expensive $500 cable (012837-001)
----------------------------------------------------------------
I intend to perform this expansion on more than just 1 node, so
I felt it was worth the effort to try and get a cheaper cable.
As I have mentioned throughout, you do so at your own risk.
The vendor from which I obtained it actually supplies the connectors
to HP/Apollo -- but there is one sticky point:
HP/Apollo uses: Mercury cable, Honda connectors
I used: Furukawa cable, Honda connectors
--------
The difference: we couldn't be sure. The electrical characteristics
appear to be very similar, but the Mercury surely has a tougher
jacket. Perhaps Apollo chooses the Mercury version because people
will inevitibly be stepping on your cable. At any rate, I have
been using my Furukawa second source for 3 weeks now.
If you wish to order Mercury cable, you must purchase 1000 feet (even
though you only need 10). With enough orders, my distributor could
combine them to make the Mercury cable economically feasible. Until
then (and perhaps forever, since that would take quite an order),
you will have to settle. Don't be too scared, I personally don't
feel this is too risky -- the bus IS terminated.
This rather long discourse on cabling is include to alleviate my
source from having to repeat this ad nauseum. Here is how you
may reach him:
George Lawton
Marathon Sales, Ltd.
776 Waverly St.
Framingham, MA 01701
USA
508-875-3566 telephone
508-879-1179 FAX
Approximate price: less than $100, much less in quantities
greater than 10.
cable assembly number: AA-80R10FA-02
I have notified him that I would to post his name in the Internet.
This is in no way a commercial endorsement, simply a second source
for a commercial product.
================================================================
Telling Domain/OS the disk is there ... Part 4
================================================================
This section assumes you are already familiar with the following
tasks of system administration:
booting a node
running CONFIG (EX CONFIG at MD prompt '>')
running INVOL (EX INVOL at MD prompt '>')
running SAX (after Domain/OS boot)
When you power up your node, you should notice that the disk
test finds the second disk. If not, better power down and check
the cable connections again. The power-up diagnostics found
it even before I ran CONFIG (set the maintainence switch, SW2,
to its `bottom' position to prevent automatic boot of the node.
Did you remember to remove the terminators on the internal disk?
See step 7 on page 2-10 of the manual.
Run CONFIG to tell Domain/OS you have added the disk.
You will need to run INVOL to low-level format your disk. Refer
to the disk with the following mnemonics:
w0:0 internal (existing) disk
w0:1 external disk 1, on same controller
as the internal disk.
w1:0 drive 0 on second (optional) controller
w1:1 drive 1 on second (optional) controller
I will make no attempt to warn you of all of the possible nasty
things you can do should you INVOL the internal disk instead of
the new one. You were supposed to back that up before you con-
nected the first cable.
Once INVOL'd, you should be able to mount the disk with the
Aegis command:
/com/mtvol w0:1 /extra_volume_1
Try an LVOLFS (/com/lvolfs) to see if it shows up. If you have
trouble with this, you might be in for a long night. Mine worked
the first time, so I cannot help you here. I told INVOL to part-
tition my 780 into 2 approximately 300 MB partitions, so I have to
add the second invocation:
/com/mtvol w0:1 2 /extra_volume_2
If you mounted the volume with the Aegis 'mtvol', do not forget
to unmount it with 'umtvol' before you attempt any of the Unix
versions of these commands.
If you are running a Unix SYSTYPE under Domain/OS, you must now
perform some additional commands to make the drive's '/dev' device
mnemonic. This is beyond the scope of this hardware lesson, but
if you have the HP/Apollo support script '/etc/mkdsk', it is rather
simplified. I obtained it from the Mentor Customer support group,
and its purpose is to make the disk device:
device relates to logical disk
--------- ----------------------------
/dev/wn1a (logical partition 1, w0:1)
/dev/wn1b (logical partition 2, w0:1)
p.s.: in my version of 'mkdsk' (dataed 89/08/21), there is
a typographical error on or about line 40:
is: if [ $4 -lt 1 -o $3 -gt 15 ] ; then
should be: if [ $4 -lt 1 -o $4 -gt 15 ] ; then
^
should be '4'
Once you run '/etc/mkdsk' to make the device number (which simply
calls the Unix utility '/etc/mknode' with the correct arguments),
the device /dev/wn1_ will exist. Then you can:
mkdir /extra_volume_1
/etc/mount /dev/wn1a /extra_volume_1
mkdir /extra_volume_2
/etc/mount /dev/wn1b /extra_volume_2
This will allow you to use the BSD /etc/mount to easily mount the
disk as a 'BSD' type device (run /etc/mount with no arguments to
see what kind you get. If you used /com/mtvol it will be of type
'Aegis'. I wasn't sure what the implications of this were (probably
minor, since Domain takes care of the filing systems anyway).
Don't foget to update /etc/fstab with your new volumes or you
will need to SALVOL it each time you reboot (ouch!). It looks
something like this:
/dev/wn1a /extra_volume_1 4.3 rw 0 0 0
/dev/wn1b /extra_volume_2 4.3 rw 0 0 0
Most of all -- good luck! I hope this is enough to get you started.
================================================================
Summary and Disclaimer ... Part 5
================================================================
After spending small fortunes on hardware and software, I found
that management was rather unwilling to provide me with enough
disk space to properly manage an efficient and quality EDA
environment. Since my primary responsibily is engineering rather
than systems administration, I felt it was critical to provide
the users community with enough disk space that I wouldn't have
to run disk sizers every night to nail users that kept more than
two copies of their designs.
I hope that this long dissertation will provide the knowledge
for the general public to make intelligent choices. Make no mis-
take, cobbling this together will take a lot of time, and you
will find it difficult to convey your sense of urgency upon either
your boss or your customer service representative should it not
appear to be working. Your best bet, as always, is:
Don't panic
Don't make assumptions (check continuity of cables)
Don't be afraid to find a `buddy' to help you; they
often can find your silly mistakes much more
quickly than you will alone.
Don't do this at 1:00 am like I did.
----------------------------------------------------------------
Disclaimer:
----------------------------------------------------------------
I am not affiliated in any way with:
Marathon Sales, Ltd.
HP/Apollo (Hewlett Packard)
Mentor Graphics, Inc.
IBM (International Business Machines
AT&T (American Telephone and Telegraph)
I have freely used Trademarks of these respective companies
throughout this article, so be sure to contact them before you
attempt to name a perfume after one of them.
----------------------------------------------------------------
My views and suggestions are my own, and not those of Racal
InterLan, Inc. (all they know is that I saved them mucho $$).
((((((((((((((((((((((((((((((((((|))))))))))))))))))))))))))))))))))))))))
(( Sr Hardware Engineer )) (( Jeff Koehler ))
(( Racal InterLan, Inc. )) (( jak@interlan.com ))
(( Boxboro, MA 508-263-9929 )) (( imagine code with this many '('s!))
((((((((((((((((((((((((((((((((((|))))))))))))))))))))))))))))))))))))))))joey@tessi.UUCP (Joe Pruett) (06/08/91)
you can also control two drives from the sms/omti controller (at least on dn4000's w/ 380 meg drives) by hooking things up in the obvious manner, and then installing the w4 or w5 (i don't feel like opening up one of my boxes right now) and everybody is happy. we have two machines running like this with a striped file system across the drives. e-mail me if you want to know more.