F/W Streaming RAID
SCSI-2 Fast/Wide Streaming
RAID Adapter/A "Cheetah" FRU 06H3059
Function of NVSRAM
HD LED Does Not Work
HD LED Hack
Cyrix/Non-SOD Type 1 Incompatibility?
Cache Size Factors
Cache Size and Diminishing
Accessing the RAID Configuration
FWSR Bios Flash Disk
Cheetah in a 85 / 95 /95A
Cheetah in a Server 500
Getting CD Rom to WORK On Server
Scientific Wild-Assed Guess Why it
Linux on FWSR?
LVD Drives on Cheetah?
Specifications For FWSR
Chaos forever! These are related.
Create and Maintain your Array
Array technology, features, classifications(FWSR)
RAID Message Table
Hotswap bays for 95A
Removing side panel from 3 bay cage
Closeups of microswitches
Streaming RAID Adapter/A "Cheetah"
Sidecard FRU 06H3060
19940517 IBM SCSI-2 Fast/Wide Streaming-RAID Adapter/A
|J1 Channel 1 68 pin edgecard
J2 Channel 2 68 pin edgecard
J3 Not connected. Or used.
J4 DASD Status Connector
J5 DASD Status Connector
J6 Possible serial port. Unused.
|J9 Channel 2 external port.
Y1 50 MHz Oscillator
Y2 40MHz Oscillator
F1 Channel 2 PTC resistor
F2 Channel 1 PTC resistor
The Cheetah has two channels. Each channel is controlled
by an NCR53C720. The header J1 is Channel 1. It usually is attached to
an internal array, but with the addition of a side card, it can controll
an external array. The second channel uses J2 OR the external port, J9.
This is still one channel, so one can use either the internal port, OR
the external port. Do NOT try to use both J2 and J9 at once.
NVSRAM is a Benchmarq 28 pin 8Kx8 bq4010YMA-200, Spec
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
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.
LED For Cheetah
BUT if you take an LED off of J6, pin 1 and 2, it will
light when the drives are accessed. Just run a lead up to between the LED
blocks in the display panel. Watch the polarity. If the LED doesn't light,
switch the header around. You do not need a resistor for this.
I tried this, but the LED didn't have enough umph. Pretty
dim through the LED Panel. Maybe some sort of a drive circuit?
Just had a thought- twist the existing HD LED out of the Op
Panel and put the LED that is connected to J6 in there....
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).
I know that the Cheetah has 4MB soldered on. This is to help
you understand WHY 4MB is probably all you'll need.
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 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 results)
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 data).
e) the 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 through".
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.
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.
RAID Flash Bios for "Cheetah"FRU 06H3059
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
Flash BIOS 2.21 Only for RAID controller WITH an external
port on it!
Flash BIOS Readme
Cheetah in a 95
The RAID bay for the 85/95/95A does not have a place foe the
status cable to attatch. The RAID bay has a 68 pin edgecard at the back
where the molex style SCSI connector attaches to. The 95 RAID bays automatically
terminate the SCSI drives inside. Do NOT enable termination on the individual
I installed a CD Rom in Bay 7. I used a 68 to 50 pin adapter
from the RAID cable connector. I have installed both NT Workstation 4 and
OS/2 on it. Both were able to detect and use the CD Rom during setup. FWIW,
I had only one bay with three drives in it.
Cheetah in a Server
Setting the CD
Rom ID in a Server 500
From Rich Nagle
Following repeated failures of NT 4 Server
setup to recognize the CD Rom connected to the passthrough connector on
the top backplane, I noticed that the CD Rom was showing up as one SCSI
ID# higher than it was when I checked it under the RAID Utility View Configuration.
After checking the SCSI ID jumper on the
backplane (set to LO for IDs 0 thru 5 on the backplane), a sudden flash
of inspiration occured- I set the CD Rom to ID 5, went back under the RAID
Utilities, and the CD Rom was now ID6. I then deleted, then recreated the
array. Now when I ran NT Setup the CD Rom was recognized automatically.
God-like SWAG of What
From Us, the god-Emperor of Microchannel
While Rich was single-handedly adding
a dollar to each share of AT&Ts stock, I noticed that the SCSI IDs
for each drive connector on the backplane went from 0 to 5. This wasn't
the blinding flash that explained everything, but I think it's the reason.
Read on to follow my logic.
Peter said he set CD Roms to ID6
for installation on one contract. But Rich noticed the odd +1 to the SCSI
ID of the CD Rom. Remember the SCSI IDs went from 0 to 5. We know 7 and
15 are used by the controller. But ID6 is NOT accounted for.
Without the inspiration of Jolt,
I was hobbled to mere human powers. Try this for a fit:
Any device (backplane or drive) attached to the
passthrough connector automatically has 1 added to the SCSI ID. The SCSI
ID jumper has something to do with setting a fourth bit for ID.
For a CD actually jumpered to ID6,
the backplane adds 1 (it's attached to the passthrough connector). The
CD Rom becomes ID7, which conflicts with the SCSI controller. The SCSI
controller asserts it's rank and shuts the CD Rom up.
Linux on FWSR
>> Is anyone running linux on one of these machines?
Not on machines with the IBM Raid controller with
the old 2.43 firmware. No Linux driver available
The IBM Fast/Wide Streaming Raid Adapter PCI as
used in the Server 320/520 MCA-PCI versions is derived from the Mylex DAC960PL
- it only has 128K Flash ROM (one 28F010 chip) but a second open socket.
Firmware 3.x requires 256K Flash. I'd tried to plug in a second 28F010
... but I think the old software contained in that chip confused the adapter
a bit ... it behaved a little "strange" (long boot time etc.)
What I do not have is an Eprommer that is capable
to write the Flash-ROMs of the 28Fxxxx series or I could a) write a spare
2.4x Flash (to keep for the "worst case") and b) clear the 28F010 ROMs
I pulled from some old boards. Else I would stuff in a blank ROM in the
second socket, have the old 2.xx in the first and run a firmware update
3.x from the DAC960PL on that adapter.
The machines with the older RAID-adapters ("Passplay"
and "Cheetah") based on MCA technology are out of the discussion anyway.
They are based on the DAC960M technology basically but an older draft of
that concept. They use some of the chips of the -M and early -Px adapters
(PL / PD) and they are developed by Mylex - but the firmware 3.x is PCI-specific,
not MCA. So you can practically forget about using them under Linux since
the driver is *particularly* written for the 3.x firmware level.
LVD on Cheetah
>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.
|| SCSI-2 Fast/Wide
|SCSI bus path / speed
||16 bit / 20 MB/sec
|I/O bus path / speed
||32 bit / 40 MB/sec streaming
(80 MB/sec on PC Server 720)
||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 3 (full length)
||Two (one internal; one internal or external)
||Two internal - 16 bit wide
(sidecard not included on Server 500)
One external - 16 bit wide
*Can only use two connectors at once
||14 per adapter (7 per max per channel)
|Cache std / max
||4 MB / 4 MB (with parity) 60 ns
||Soldered on adapter
|Cache write policy
||Write-through or write-back