Setting up CyberstormPPC scsi... sync, luns etc etc

[Robert17]

Hey all, need some help with the uw-scsi controller on the csppc. Been trying to tune it, using sync. etc, can someone tell me what LUNS are? also I keep getting phase missmatch, parity errors and blockid errors, when I try to use my cd-rom. The Hard drives work a-okay until I try to use my cd-rom, its's a plextor 40x

Robert

[billchase]

LUNS I believe are associated with devices like CD Changers and maybe
some other removable media type drives. For hard drives and plan ole CD-ROMs
use a LUN value of zero. The errors you are reporting sound like possible
termination issues. Can you describe how your scsi chain is set up?

Just to doublecheck some things, make sure your devices are actually using unique
ID numbers. Also, try putting the CD-ROM at the end of chain if it is not already.

C Snyder

[Robert17]

Okay, my scsi chain...

Controller ID=7 (start of the cable)
Hard disk ID=8
Hard disk ID=4
CD-rom ID=3
Active terminator

End of cable

All devices are set to 8 LUNS I thought setting to No LUN would disable the device.

Robert

[doctorq]

I thought setting to No LUN would disable the device.


It does

[Robert17]

So how do we decide how many LUNS a device should be given?
Also what should a SCSI cdrom with 50<->68pin adaptor be set to in the scsi settings?

Robert

[x56h34]

An active terminator before the CSPPC is also required. CSPPC offers no on-board termination.

[Robert17]

but my other csppc doesn't have one either, and that works fine (I think)

Robert

Edit: or maybe the problem only comes into play when using Synchronus mode... I'll modify my own setup later.

[x56h34]

It works but probably by coincidence. This is an example of how the chain needs to look:

Terminator---Device A---CSPPC---Device B---Device C---Termnator

[Robert17]

Okay, do they have to be active or passive teminations?

And how do I decide how many luns to set to my devices?

Re-selection etc can that be left to auto?

[x56h34]

They need to be 68-pin UW SCSI active terminators or better that can fall back to UW SCSI.

Passive don't exist in such flavor, I think (only for 50-pin SCSI-2 chains).

[Robert17]

okay so I can't use a scsi-2 terminator on an adaptor for example?

[x56h34]

No because there are no 68-pin SCSI-2 terminators. It's impossible to make such a mistake.

Anotehr option is to put the CSPPC in the middle of the chain and place a hard drive with on-board active termination on one end, and your existing stand-alone terminator on the other end.

[Robert17]

okies, I think the guy who owned it before had it set up to go to an external 68pin connector with a terminator on it, but I removed this part since it's how my other system was, silly me. The plug is still on the case, I'll have to see if I can dig up that terminator later

Thanks a lot for your help :-D Hopefully before long I can use the scsi to it's full potential, until today I was going at 7mb/s...

[x56h34]

I get slightly above 30MB/s with CSPPC SCSI, however I am using a nice 18GB server class 10000rpm IBM hard drive, so that may have something to do with it too :-), however I believe that you should be able to achieve higher speed.

Make sure you select synchronous transfer from the CSPPC early boot menu in order to be able to reach these high speeds, and that goes for every device in your chain.

[billchase]

My mistake, set it to one LUN. You only need a higher LUN value for something
like a changer. If you had a 6-disc changer, it would get a LUN value of 6.

Like the others have mentioned, the cyberstorm scsi is very picky about how it is terminated.

Here is how mine is setup:

Active Term ---- CYBPPC ---- 68pin HD ---- CD-ROM ---- Active Term

Alternate Setup:
Active Term ---- CYBPPC ---- 68pin HD ---- CD-ROM w/termination enabled

This setup requires the use of an adapter that has the upper 8bits terminated on the CD-ROM.

Using sync vs. async is the key to getting the extra speed out of
your hard drive. It will not make as much impact on the CD-ROM speed.
It is best to set reselection to auto, but once you get your temination issues
sorted, you can experiment with it and the offset values to see what bumps
your benchmarks up.

C Snyder

[Robert17]

Okay, got my active terminators at both ends... but when I try to encode an MP3 using secondspin, I get Phase mismatch with unit 3 (cd-rom) then the other 2 drives chuck out errors too, but just moving files from one drive to another and general use there are no errors.

Robert

[Kraftwerk]

Does this only happen with Secondspin? Or after any access of the CD-rom?

See if you can change the parity setting of the drive itself with the jumpers on the back.

Also, check the settings of the CSPPC config by holding the ESC key at bootup.

[yogisumo]

Robert17 wrote:
Okay, got my active terminators at both ends... but when I try to encode an MP3 using secondspin, I get Phase mismatch with unit 3 (cd-rom) then the other 2 drives chuck out errors too, but just moving files from one drive to another and general use there are no errors.

Robert

Make sure you're cabling isn't too long.
Some devices don't play well with other scsi devices.
Start troubleshooting with only one device on the bus.
Add devices one at a time.
It's best to use terminators on the cables as opposed to onboard hard drive/cdrom termination simply because it makes changing things around so much easier.
Different devices SCSI 1/2/3 16/32 bit have different maximum cable lengths. When you mix them, make sure you're not exceeding the shortest max length.
Read the scsi faq http://www.scsifaq.org/

[Robert17]

@ Everyone

It's all working now, MP3 encoding too :-D

[quenthal]

@Robert

Nice! Btw., what speed do you get now from your devices, and what was the problem? What settings did you fiddle with to get the best speed?

[Chain]

I have problem with CSPPC too... i dont have any, damn!

[Sparky]

*shudder* the storage specialist in me is cringing from the setups I saw described here! Some were OK some horribly horribly wrong :-(

OK first up a LUN is a Logical Unit Number, a device can have more than one LUN presented from it (hard disks usually just present one, CD changers as mentioned can have multiple, and storage arrays can present multiple LUNs (ie. you split a big RAID into chunks, each appears like a seperate disk on the one device)), what a SCSI device does when it finds another device on the bus is to see how many other devices are on the ID .. the LUNs.

Next, the CyberstormPPC is a strange beastie in that for some reason Phase5 didn't include the option to terminate on it (could be cost or they just forgot) so for it to work properly BOTH ends must have active terminators. Also the CSPPC SCSI is Ultra Wide which is a 16bit wide bus, all 16bits must be terminated at both ends of the SCSI chain ... this is important (see why in a mo).

Terminator power to the bus is also important as the active terminators need power to work basically, at least one device on the SCSI bus can provide the power (disk usually has a jumper caller TERM PWR or somthing), doesn't matter too much if multiple devices provide TERM Power but be aware that the more that do means more current on the bus.

Basic config would be :

Terminator -- CSPPC(ID 7) -- Disk(ID 0) -- Terminator

this would be using 68way cable, 68wayactive terminators and a 68way Ultra Wide SCSI disk.

Your config would go like this :

Terminator -- CSPPC(ID 7) -- Disk(ID 0) -- CDROM(ID 5) -- Terminator

I'm making an assumption here that you have an Ultra Wide SCSI CDROM (68way) .. if you have a Narrow SCSI CDROM then you CDROM is only 8bits wide (this is the important bit I mentioned earlier) in order to get this on the 68way bus you need a 68way to 50way converter, easy to get hold of, and then plug it into the 68way cable to give you your 50way for the CDROM.
Now you're probably thinking that you can just use the CDROM as the final Terminator as it can terminate on board, well DON'T ... if its an Narrow SCSI CDROM then it would only terminate the lower 8bits of the bus, the upper 8bits would be unterminated leading to "oddness" on the bus.

Parts you'll need are :

UltraWide (or Ultra2/Ultra160/Ultra320) SCSI cable with 5 connections.
2 * 68way Active Terminators
1 * 68way to 50way SCSI adapter

Have any questions just send me a message :-)

[yogisumo]

Robert17 wrote:
@ Everyone

It's all working now, MP3 encoding too :-D

Ok. So what was the problem?