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IThinkDifferent
07-26-2005, 12:00 PM
Greetings Gurus!

I have 3 Seagate ST150176LC Barracudas that I'm trying to set up for an external RAID.

So far, I've used the info in your "Roll Your Own Raid" as a guide...pretty straightforward

mostly...although I did have to read how to configure my jumpers more than once (ha!)

I'm reasonably sure I understood enough to get it right...you tell me

Force single-ended bus mode: jumper off
Delay Motor Start: jumper off
Enable Remote Motor Start: jumper off
Write Protect: jumper off
Parity Disable: jumper on
Reserved
Term. Power to SCSI Bus: (applies to “LW” model only; reserved on LC” model)

Now, how the heck do I set the last one if its reserved?

Here's my system info: PowerMac G4 Digital Audio w/ Sonnet Encore ST 1 Ghz/40 GB WD
(boot disc) 1 GB RAM / Initio Miles U2W / Mac OS 10.3.9

As always, any and all info is greatly appreciated!

TZ
07-26-2005, 12:17 PM
Configuration:
http://www.seagate.com/support/disc/scsi/st150176lc.html

INTERNAL FORMATTED TRANSFER RATE (MB/sec)_19.1 to 33.0

Specs:
http://www.seagate.com/support/disc/specs/scsi/st150176lc.html


Note: LW and LC drives do not have internal terminators or
any other way of adding internal terminators to the
drive; use external active termination if required.
Use active (ANSI SCSI-2 Alternative 2) terminators
when terminating the bus. Use active negation
terminators when terminating a SCSI Ultra2 bus
operating in Low Voltage Differential (LVD) mode.

Would usually try to steer people away from using multiple SCA drives. To use Granite SCA adapters only.

they are meant to be used with SCA backplane ($$$) and setup would be easier using LW versions. MilesUW is also a limiting factor. A single 10K drive currently shipping (73GB 10K $220-240) would run circles around such an older technology. Or SATA setup. PATA/SATA drive would deliver 55MB/sec. A single 36GB 15K drive would do nice for scratch probably as well.

kaye
07-26-2005, 03:05 PM
Miles2 can make use of Parity if enabled. Termination and Termination Power are two different things. Termination Power is supplied by Miles2 and you do not want two sources of Term Power unless a very long SCSI cable is being used. k

IThinkDifferent
07-26-2005, 05:47 PM
What I wanted to know is what do I do about the TE/TP option on my drives?
Do I just ignore that option and use a terminator on the end of the bus?


BTW I know this is old stuff...but reading your "How to roll your own RAID" guide got me thinking about all the extra stuff I have...a quick inventory of what I had just laying around yielded 15 Barracudas.. as well as enough cabling, terminators and yes, Granite SCA adaptors to build several RAIDS already...so why not?