[Info-vax] Best way to get what I can off a failed VMS Disk?

[Simon Clubley]

On 2020-10-24, Phillip Helbig (undress to reply) <helbig at asclothestro.multivax.de> wrote:
> In article <rn1ids$78o$1 at panix2.panix.com>, kludge at panix.com (Scott
> Dorsey) writes: 
>
>> Get a drive image as soon as possible.  You can do it on the Alpha, you
>> can pull it off and put it on a PC with Clonezilla or with dd, although
>> the best thing to do is to drop it into one of the offline disk duplicators.
>
> Would forming a shadow set be slower than an offline disk duplicator?
>

Will forming a shadow set cause random I/O all over the failing
disk or will the disk be read exactly once from start to finish
in strict sequential order without any additional I/Os ?

Lots of extra random I/O is very bad on a failing disk.

Simon.

-- 
Simon Clubley, clubley at remove_me.eisner.decus.org-Earth.UFP
Walking destinations on a map are further away than they appear.