SCA Hards How do I make it the primary Drive

[Omega81]

Hello guys I just need a little help please. I have a SCA 80pin SCSI 9.1GB Hard Drive. I
want to make it my primary HDD and install linux on it, but when I plug in the adaptor, and connect it to my Adaptec 2940uw card, It don't work. It is detected but I can't format it with the adaptec program on the SCSI cards. I heard something about them not having internal to terminators but how do I solve this problem and is that the only problem I will have. Please help
thank you

 

[InsanityRmx]

Omega81-

SCSI busses - internal or external - must be terminated at both ends. It's pretty obvious how you do this on external SCSI device chains. Most external devices have two SCSI connectors (IN and OUT or whatever). Your controller automatically terminates it's 'end' of the cable. The last device cabled on the chain will have an empty connector. A stubby little terminator plug often needs to be used in that empty connector for the rest of the chain to work properly. In some cases, the devices may have some auto terminating circuits so you don't have to do this.

When using an internal ribbon cable, your Adaptec controller again terminates it's 'end'. But you must supply termination at the last device on the ribbon cable.

CAUTION #1: Some SCSI controllers have both an internal and external connector for the same SCSI channel - I think yours does. If you're already using the external connection, then it's probably already terminated properly. (Ignore the rest of the paragraph if you're not using the external connection) If you're also using the internal connection, then you have to 1) disable termination on the controller and 2) make sure you terminate the last device on the internal ribbon cable, too. It's OK for the adapter to be in the 'middle' of a SCSI chain as long as both ends are terminated properly.

With that in mind, you have to consider how to terminate your drive. They don't have two connectors like external devices, so it's not obvious how you do this. If you were using a 68- or 50-pin drive, you would usually find a jumper on it that enables internal termination (it's never automatic). Your SCA drive *may* have a termination jumper, but they're becomming less common (reply with the drive model if you can't determine). BTW, SCA drives are usually used in multi-drive installations; the rack/cage handles termination, not the drive itself.

No termination jumper on drive? Check your SCA to ribbon cable adapter. Some of them have a termination feature (usually a jumper) built on them. They're a little more expenseve then the 'plain' SCA adapters, but you only need to use one of them on the last drive on the ribbon.

Still no luck? You have two remaining choices: buy a little pass-through adapter for the ribbon cable itself, or buy a 68- or 50-pin to SCA adapter *with* the termination option. It's probably cheaper to replace your SCA adapter with one that offers termination. They're something like $20 on ebay - a little more expensive than the 'plain' ones. Active termination is prefferable to passive - go with it if it's only a few bucks more.

I seem to recall the termination pass-throughs for the ribbon cable were more like $40 - 50, but you might want to check the web. If you can get one cheaper than a new SCA adapter, go with it.

If you do buy a terminating SCA adapter, save your 'plain' one. It will work just fine for a second SCSI drive on the cable.

CAUTION #2: Low-level formatting your drive fixes and prevents nothing, period. It could actually result in screwing up the performance of a SCSI drive - you don't need to do this. It's a relic of the early 90's simple drive layouts. The manufacturer of your drive figured out a much more complex optimal sector layout specific to that drive. There is simply nothing that fdisk or one of the commercial partitioning programs can't overwrite or fix on a good drive. If they can't or if you need to "clean-up bad sectors" for some reason, then the drive is *really* screwed up. Low-level formatting may make the drive useable again (if it's unuseable now), but the sectors will probably not be layed out for optimal performance.