Tuesday, August 30, 2005

The great thing about standards...

You know the old chestnut: The great thing about standards is that there are so many to choose from.

Now SCSI is a great standard. The truth is that SCSI devices do interoperate
incredibly well. At that level, it's been a phenomenal success.

But SCSI really covers a lot of things. The thing that hit me recently was connectors and cables.

I remember old SCSI cables with DB50 and centronics connectors on. I don't remember using them much - they were being phased out when I started playing this game. Then came the small 50-pin connector. Then the HD68, and more recently the VHDCI connector. Did I forget anything?

And then of course there was original SCSI, fast SCSI, fast wide SCSI, FWD, ultraSCSI, and ultra320 SCSI. And single ended plus two variants of differential.

So it's not actually that easy, given a system and a device, to say whether they will in fact interoperate. And then you need to find the right cable. (And then is the cable rated for ultraSCSI speeds?)

Which has bothered me for a while, but recently came to the fore after a bad incident caused a system to fail. So I decide to move the disks from a Netra T1 to a V240 and run the services in a zone. Easy, right? Well, not quite. The T1 has a HD68 orifice as I recall, and I think the V240 has a VHDCI outlet on the back!

So I go for a rummage in the loft and find the right cable. I'll send that across to the machines, and hopefully will be able to set the zone up and have the service back operational later this week.

1 comment:

FithisUX said...

However one of the things SCSI spec does not cover is how to drop the prices and make itself available to everyone :-)