Clicking SCSI disks

Bill Degnan billdegnan at
Mon Sep 7 12:39:16 CDT 2020

On Mon, Sep 7, 2020 at 12:57 PM Antonio Carlini via cctalk <
cctalk at> wrote:

> I have a number of old (2000-era) DEC StorageWorks disks that fail to
> mount under VMS. They report MEDIUM OFFLINE.
> They power up in a similar way to other disks that do work, but they
> persistently click ina  "something isn't right" manner.
> I've tried reorienting some of the disks to see if that makes any
> difference, and for the ones I've tried, it didn't help.
> I've read about the "freezer" trick, but mostly I've seen negative
> opinions. However, those opinions mostly come from data recovery
> specialists!
> So I thought I'd tap the wisdom of the list. Is there any way that
> people have used to successfully recover data from RZ28, RZ29 disks
> (which all worked in 2003 :-))? Has anyone tried freezing a double
> bagged drive? Was it successful? If so, how long did you freeze it for?
> These disks are in StorageWorks containers ... should I remove them
> before freezing?
If there is no stiction then tapping the disk or opening to spin the disk
manually does nothing useful IMHO other than expose the surface to dust.
It could be that you need a new controller, you could always try a
transplant of the controller electronics from one drive to another to dump
the data.  Has to be the same type of drive, etc.  It's all a percentages
thing, you might save one out of 4 swapping around electronics.  If you
have nothing to lose and you don't mind possibly making it worse ...

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