[Info-vax] Backup A Dying Disk.

[Jerry Weiss]

On Tuesday, March 17, 2015 at 3:00:37 PM UTC-5, Stephen Hoffman wrote:
> On 2015-03-17 17:20:13 +0000, wa2flq said:
> 
> > I have RD54 disk that that whose entropy is rising. Someone who doesn't 
> > have a backup asked me to save what I can before it dies completely.  I 
> > realize its probably a goner, but I want to give it a shot.
> 
> Why?  If you know of specific directories, grab them and run.  Don't 
> bother with the whole disk.
> 
> > I can mount the drive read only with error logging turned off, but 
> > trying to do a backup is painfully slow.  Between the high number of 
> > defects and read retries, it is taking forever.   Is there a way to 
> > turn down or suppress the number of retries so I can grab the readable 
> > content?  Or is there another utility that can be used to grab an image 
> > (good and bad bits) from the drive ?  Its a MicroVAX II running VMS 
> > 5.5-2 (booted on a good drive).
> 
> Slow?  It's a MicroVAX II.  Those things are glacial.

Its all relative.  My first VAX was 11/750.

> 
> If you don't know what's on the disk, then let BACKUP run to 
> completion, and for as long as it takes.
> 
> The more that disk is accessed including by BACKUP, the more times 
> BACKUP is restarted, ^Y and all the rest, the more sectors disappear 
> forever.
> 

The housekeeping on this system was non-existent, so I'm doing a backup/image and will leave the forensics/salvage to later.    If there is no way to set IO$M_INHRETRY globally for the drive, I'll just wait it out.

Thanks for the quick feedback.