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

[geze...@rlgsc.com]

On Saturday, October 24, 2020 at 8:49:42 AM UTC-4, Chris Townley wrote:
> I have a failing ODS-2 disk in my Alpha (HPE VMS 8.3) 
> 
> What is the best way to recover those files that are recoverable, with 
> the drive going into mount verify? 
> 
> Thanks 
> 
> 
> Chris
Chris,

It depends upon the reason for the MOUNT verify. If the problem is one or a few bad blocks, it may be possible to reconstruct by obtaining information from an earlier backup and doing a form of custom merge. It can be done, but it is a tedious process.

For a start, I would try to see if it was possible to MOUNT/FOREIGN/NOWRITE and do a physical BACKUP of the drive.

Before commencing this journey, it is important to consider the importance of the files on the failing disk. If the file can be recovered from a backup without great loss, that is the more economical path. If there are high-value files on the drive in question, the more exotic measures can be considered. There is no generic answer. If only one or a handful of files are of high value, efforts can be undertaken to locate and collect the blocks associated with THAT file or files, and recovering the balance of the data from backups.

- Bob Gezelter, http://www.rlgsc.com