[Info-vax] Question about IDE disks

[Richard B. Gilbert]

JF Mezei wrote:
> Just as a sanity check.
> 
> With proprietary disks such as RA and DSSI, VMS had very good control
> and more importantly notification of errors which would then show up in
> the SHOW DEVICE output.
> 
> There was a phase in time where Alphas supported el-cheapo (made for
> Windows PC)   IDE (now called ATA) disks.  (models such as DS10/DS10L
> for instance).
> 
> Do those drives (and IDE protocol) give VMS the same level of
> notification as previous generation of disk protocols ? Or do they
> perform their own internal disk maintenance without bothering the OS ?
> 
> In other words, if an IDE disk is starting to make weird noises, does an
> error count of 0 on the SHOW DEV provide some indication that the noises
> have not resulted in problems with actual disk operation, or could the
> disk already be seriously sick and just not reporting its problems to
> the OS ?
> 

I've had IDE disks running almost continuously for several years.  While
failure is possible it is not very common.  IDE is only the interface 
electronics.  I think that virtually all disks have the same sort of 
enclosure, the same sort of platters, the same sort of heads.  What 
differentiates them is: capacity, performance, reliability, and 
interface with the system.