In <[EMAIL PROTECTED]>,
on 01/07/2005
at 01:16 PM, "McKown, John" <[EMAIL PROTECTED]> said:
>Thinking back on the SLEDs of yesteryear, they had a format wherein,
>if a section of the drive "went bad", a "skip displacement" might be
>able to be assigned which would allow the rest of that physical track
>to be used.
Only certain drives. The S/360 DASD and the original S/370 DASD did
not have skip displacement, although they did have alternate tracks.
>But I'm wondering, do current drives have some sort of capability to
>continue being used despite a small number of errors?
Yes; the details vary. More precisely, current DASD subsystems have
the capability, even if the individual drives don't.
>Or is the drive simply replaced once it develops any problems?
The Devil is in the details. For some types of soft failure it is
prudent to replace the drive; for others it is safe to continue
running.
>What do DASD vendor do with the drives that "fail"?
It depends.
--
Shmuel (Seymour J.) Metz, SysProg and JOAT
ISO position; see <http://patriot.net/~shmuel/resume/brief.html>
We don't care. We don't have to care, we're Congress.
(S877: The Shut up and Eat Your spam act of 2003)
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