SCSI-2 RAID Controller
"Passplay" FRU 92F0335
Function of NVSRAM
IML Limits of Passplay
HD LED Does Not Work
Cyrix/Non-SOD Type 1 Incompatibility?
Cache Size Factors
Cache Size and Diminishing
Generic 30 Pin SIMMs for
Accessing the RAID Configuration
FWR Bios Flash Disks
BIOS Release Features
Complex BIOS Levels
Slots Passplay Fits
LVD on Passplay
Specifications For FWR
Stuff that is relevant, but chaotic... (fits, doesn't it?)
Create and Maintain your
Array technology, features,
RAID Message Table
Hotswap bays for 95A
Removing side panel from 3 bay cage
Closeups of microswitches
Fast Wide RAID Adapter
There is NO external port on the
The 28 pin 8Kx8 NVSRAM is a Benchmarq, bq4010YMA-200,
Another equivalent is a Dallas DS1225Y-200, spec
Each NV SRAM has a self–contained lithium energy source and
control circuitry which constantly monitors VCC for
an out–of–tolerance condition. When such a condition occurs, the lithium
energy source is automatically switched on and write protection is unconditionally
enabled to prevent data corruption.
The mini C68 for the Channel edgecard connectors is the
part# 15-92-3068, called a half pitch Centronics, or a VESA Media Connector.
Suprise! AMP makes a similar part (mini-C68) AMP Part 1-557089-2
Any cable with a .025 pitch, 28 to 30 AWG will work with either connector.
Don't ask if you can get this cable for $9.99! I have priced
out the black sheathing, twist 'n loose 68 wire cable, and the molex connectors.
If you bought the cable by the 100' reel (if you can get it shorter, tell
me) and the sheathing the same way, the parts alone cost upwards of $50
for a replica of the original FW RAID cable. Can't run with the big dogs
if you are whining with the pups.
No, I do NOT have a pile of them in my closet! No, I do
NOT know where to get them at $5 each. No, I do NOT know how to make a
replica for $10. It's your data. If
you want to cobble a cheap cable up, I suggest buying SCSI-III flat cable
from Dalco and crimping on the needed Molex/AMP connectors. But don't blame
me if you loose something.
A Better Cable Hack?
Allen Brandt wrote:
> A small, shotty attempt to get something uploaded concerning the
My Take on it:
I am starting to have neurons fire. Actually, Allen provided
the push. Al went and slit the conductors for better flexibility (in pairs).
Could you slit the flat cable up towards the controller
and get the very flexible cable bundle of the IBM original? The black sheathing
is available from Jameco for about $1 a foot. Well worth it, IMHO. (Start
the slit with an X-Acto and use the reverse of the blade to finish parting
The sheathing is Techflex Cable Sleave, looks to be the
3/8" size. Sold in a 25' spool. Part #162157,
Product # CCPT2X per spool $14.95 Techflex is HERE
What kind of signal degredation might occur? Each signal pair hopefully
cancels it's noise out.
If the Brandt manuever can be done from the top drive
connector to theadapter, it might be a close match to the real thing
The Passplay was introduced for use with non-Flash systems.
However, the Passplay does NOT support Int13 or IML. You either have to
boot from a floppy or from an IBM IML capable SCSI adapter. A telling sign
is the Type 5 form factor card cutouts in the case are on Slots 2-4. A
Type 3 form factor SCSI Adapter has to be installed in Slot 1 to support
Type 1 and Type 2 complexes that do NOT have the enhanced BIOS.
HD LED Doesn't
>Is i a fact that the HD LED does not work on a 9595A with a PassPlay
The fixed disk light is non-functional with both the Server
95 A "Passplay" and Streaming-RAID "Cheetah" MCA RAID adapter. I
suspect this is also the case with other OEM'ed Mylex RAID adapters.
Just thought that I'd better warn you.
After checking out the Cyrix 5x86 at 4x clocking (in Type-1 non-SOD w/cache)
my PassPlay RAID adapter seems to have been "duffed up". I only get a part
of the BIOS v1.05 initialisation/installation message and the machine hangs
(with *any* CPU) at CP:96. Looks as though the Flash ROM has been partially
overwritten (just a guess).
How important is the amount of cache ram on the PassPlay
RAID adapter--4 MB, 16 MB, 64 MB? Under what circumstances will a
cache increase pay off? (The system in question is running NetWare 4.1,
but I'm interested in general info on this subject.)
I notice that the more recent Cheetah RAID adapter has
only 4 MB with no upgrade possible. It seems counterintuitive, but
I seem to remember reading somewhere that large amounts of controller cache
aren't really that useful with modern drives and operating systems.
Having a large cache is only half the truth. Bigger cache
means more damage if the controller chokes and cannot write data back to
the drives. Large caches on Raid controllers make sense only if they are
battery-backed (Ed. I have seen
battery-backed 72 pin SIMMs) and if there is a mechanism that allowes to
remove the cache (with the data), replace the adapter, plug back the cache
and restart the system to that point where the operation was stopped and
write the cache data down to the drives and maintain the integrity of the
data / array.
The older Raid-controllers (Server-95 Raid "Passplay",
Fast/Wide Streaming Raid /A "Cheetah" and Fast/Wide Raid PCI "DAC960")
don't have battery backed cache. Even 4MB of cache memory contains a large
number of "data-stripes" (usually 8K blocks).
These data-stripes will be lost if the machine powers
down for any reason, or the controller fails, or the operating system hangs.
Recalculate how many sectors fit in 4MB - and the higher the number of
missing sectors the lower the chance that the Raid-Utility will be able
to restore the missing data.
a) Overall drive data-throughput (buffering x accesses while drives
are in *mechanically* causes delay / dead zone / recalibration)
b) Data-stripe size (8K normally - 64K under WinNT might give better
c) Operating system (WinNT and OS/2 are very "swap active")
d) Structure of the RAID itself (Raid-5 uses the cache much more than
Raid-1 ... because the mirroring is imminently fast with buffering the
e) Nature of the data blocks. Consequently high internal redundancy
of the data will cause higher "hit rates" within the cache than permanent
data-streaming with new data, which void the cached data and only "pass
Like on all caches there is a limit where enlarging the
cache any further makes no sense. And I think this limit is at around 4MB
on a 5 drives Raid-5 system running under OS/2 or WinNT. The content-redundancy
of the data is mostly not given - so the cache is mostly used to buffer
the Raid data-overhead between the drives (during reading / writing / synchronizing
the Raid structure) - on the transfer between drive-subsystem and processor
the cache does not play a major role.
A larger cache here costs only money and bears the above
mentioned risks to render the entire array useless if something crashes.
and Diminishing Returns
Generally speaking, increasing the amount of cache will
always improve performance. The performance gain will be more for sequential
access type applications than for random access type applications. Typically
increasing the cache from 2 to 4MB will see a bigger % gain than 4 to 16
MB and that will see a bigger % gain than 16 to 32 MB and so on.
IBM or Generic
They are 30-pin standard industrial ("generic") SIMMs.
Since the original concept allowed 4x1MB, 4x4MB and even 4 x 16MB cache
Simms they *must* be generic, because IBM only coded the 256K, 512K and
1MB modules. The 4MB and 16MB are not on IBM's list.
the RAID Configuration
Both the FWR (Passplay) and FWSR (Cheetah) are only configurable
through the RAID Utilities disk. You CANNOT see the SCSI Disks under "Set
and View SCSI Devices" like normal SCSI drives. Boot with FWSR
Option Disk, #1 ver. 2.31 in order to view or configure the array.
Both adapters use the same Utilities disk of the later
IBM F/W Streaming RAID Adapter /A (Codename "Cheetah" - with external port)
since both are based on Intel i960 / Mylex / NCR technology. There was
a single-disk version 2.22, which should be unique for all /A-Raid adapters
of that kind, but not the PCI-versions. The RAIDADM
(manager) should work on both /A-adapters.
Utility version 2.31 consists out of two disks:
Option Disk, #1 ver. 2.31
Option Disk, #2 ver. 2.31
for FWSR Option Disks
Not sure if this fits-
Supplemental Diskette Version 2.0 And the Readme.txt
RAIDSEND is a utility that provides an OS/2 ONLY command-line interface
for performing various tasks on a IBM F/W Streaming RAID Adapter/A, the
IBM SCSI-2 F/W PCI-Bus RAID Adapter, and the Mylex PL adapter for the IBM
PC Server 704.
NOTE:All systems, except the 95-466,
95-560, 95 A-466, 95 A-560 and 9585-0Kx, require that the standard SCSI
adapter or system board resident SCSI controller remain connected to the
IML and/or boot hard file.
RAID Flash Bios for "Passplay" FRU 92F0335
The Passplay and the Cheetah differ in the microcode,
which *may not* be interchanged. The Passplay (FWR) adapter uses
a microcode-level 1.6x through 1.99, the Cheetah (FWSR) uses 2.xx levels.
If you flash the one adapter with the code from the other you end up in
non-functional adapters. (See the README
coming with the 1.99-level microcode update for the Server 95 RAID adapter)
Flash BIOS ver. 1.61 Only for RAID controller WITHOUT an external port
Flash BIOS ver. 1.62 Only for RAID controller WITHOUT an external
port on it!
Flash BIOS ver. 1.63 Only for RAID controller WITHOUT an external
port on it!
Flash BIOS ver. 1.99 Only for RAID controller WITHOUT an external
port on it!
for raid199a.exe (Server 95A RAID Flash disk version 1.99)
95 Array RAID API Module (Non-ASPI)
From Hakan Gadler
By the way, why did they jump from version >1.6 something
IBM "unified" the version numbers for the BIOS and the
microcode a bit. Or - to be precise - the return codes. The later Passplay
codes ran along with the same RAIDADM software that was used by the "Cheetah"
and contained some better infos and other tweaks for performance / safety
The initial code worked only with the early Passplay board
Official shipping code at the time the systems were widely
available 1.61 had some bugs with drives other than IBM 1.0GB (particularly
with the Maxtor MXT-540S in the "small" array configuration).
Contained information used by the 90MHz upgrade board
- it is mandantory if your 95A uses the "big" platform. (Ed.
The Passplay sometimes set drives into "DDD" (Dead) state
when they failed to come on ready in a very, very short period of time
after power on. 1.63 should fix problems with the DFHS 2GB drives (later
microcodes - successor of the 0664) and the "dead drive" symptom.
As far as I recall IBM recommended to use this code in all machines that
have more than 3 drives installed and the Pentium platforms (My guess:
problems with the power supply and signalling problems caused by DC-ripples).
From 1.63 on you could use the same RAIDADM and the later ServerGuide Raid
Manager for both adapters. Previous versions seemed to have delivered slightly
odd codes that caused confusion.
IBM announced the code "out of blue sky" and I wondered
why, because the Passplay was already discontinued at that time. The 1.99
codes contained some fixes for "other systems" than the 95A. It was the
last code announced for the Passplay.
There are however some dependencies between the Raid-adapter
microcode and that of the complex. You should not run the Raid with a complex
BIOS below 03. The BIOS 10 has been announced to fix Y2K problems with
OS/2 AFAIK. If you flash the complex to10 and keep the old Raid microcode
you might run into problems. It should be 1.63 at least - especially if
you have the P90 platform, which appears to the Raid microcode as Server
500 with the differing backplane layout - the return codes to the RAIDADM
then might not reflect the "real" position of the drives on the backplane.
The Passplay is a Type 5 form factor card (it's big). There
are cutouts in 95 and 95A cases that will allow the edge of the card at
the bracket end to fit. Dennis Smith turned me on to them. Slots 2-4 have
these cutouts- The 95s don't have a cushion in them, 95As do.
LVD on Passplay
>What kind of drives does the RAID take? Is FAST/WIDE
DIFFERENTIAL SCSI the right kind? Or are LVD (low voltage differential)
different and it needs them instead? I've never dealt with RAID before.
Remember the "Cheetah"-Adapter's
"Real Trade Name" ? IBM Fast/Wide Streaming Raid Adapter /A.
It it an ordinary Fast / Wide indended
for single-ended SCSI devices. It does however take U/W LVD drives, because
these are downward-compatible to single-ended, which the old
"high-voltage differential" are *not*.
If you get - for
example - a set of U/W "Low Voltage Differential" (LVD) IBM DDRS 4.5 or
9.1GB drives then they will nicely run
with the Cheetah. I have some of them in "Starship" - my Server 520 attached
to the Fast/Wide RAID Adapter PCI. No problem. You can even mix them with
"ordinary" F/W or U/W drives. Same for the Cheetah and even the older Passplay.
for FW RAID
|| SCSI-2 Fast/Wide
|SCSI bus path / speed
||16 bit / 20 MB/sec
|I/O bus path / speed
||32 bit / 40 MB/sec streaming
||Streaming data transfer
Address parity and data parity
||RAID 0, 1, Hybrid 1, 5
4 ind (A, B, C, D) / 8 logical arrays
|Tagged Command Queuing
||i960 at 25 MHz
||Type 5 (only fits Model 85 or 95)
||Two (both internal)
||Two internal only
||7 devices per adapter
|Cache std / max
||4 MB / 64 MB (with parity)
||4 sockets for 30 pin 80ns SIMMs
||4, 16, or 64 MB only
|Cache write policy
||Write-through or write-back