[Info-vax] analyze/disk errors

[Simon Clubley]

On 2013-12-06, Stephen Hoffman <seaohveh at hoffmanlabs.invalid> wrote:
> On 2013-12-06 06:19:40 +0000, Paul Sture said:
>
>> Popcorn anyone?
>
> Some folks are just good choices for quality, documentation and testing 
> projects.  Some folks can find and identify the darndest bugs, and 
> pursue them with gusto.    As was mentioned upthread and in an earlier 
> era, I'd be working to offer access to beta software to these folks, if 
> not them to the testing team wasn't on the table,  (Folks often 
> underestimate the value of the ability to break stuff; it's a skill.)
>

The problem with us programmers is that we tend to have highly structured
and boolean logic type mindsets and sometimes we need people who don't
have that type of mindset to break our code. :-)

> It never would have occurred to me to try to "repair" BADBLK.SYS here, 
> nor apparently did this thought occur to whoever was testing the 
> ANALYZE /DISK tool.  (Unfortunately, disk errors are like other 
> hardware errors; they seldom perform as expected and when desired.)
>

Does analyze/disk check the FIDs on all the reserved files ?

Obviously, that's a bit meaningless for, say, 000000.dir, but what about
some of the other FIDs ?

> Which reminds me: might anyone have a stash of bad 2.5" SFF SAS or SATA 
> disks in a drawer, and that they might be willing to part with a few?  
> I'm looking at hacking around in the area of device errors, and might 
> be looking for some bad disks for error-management "target practice".  
> (Might end up reposting this part separately.)
>

Unfortunately no, but you have just brought back some memories. :-)

Back when I was writing my ODS-2 reader, I used to have a bunch of floppy
disks with bad sectors to see how VMS handled them.

I don't know if it's just me, but I think disk failure patterns have changed.
Back in the 1990s, I did see disks with bad sectors developing over time,
but these days, I can only think of one disk over the last 5 years or so
which developed bad sectors while continuing to stay online.

Most of the time these days the disks I have experience with either start
to fail by dropping offline and then maybe comes back online after a power
cycle before dropping off again, or just outright fail with no warning.

Simon.

-- 
Simon Clubley, clubley at remove_me.eisner.decus.org-Earth.UFP
Microsoft: Bringing you 1980s technology to a 21st century world