[Coco] [OT] Rainbow on disk RAID

[John Guin]

Boinc is the Berkeley Open Infrastructure for Network Computing  http://boinc.berkeley.edu/

It's the replacement for SETI at Home.  Basically, you install a screensaver type of app that kicks in and runs some analytic task in the background and uploads results every half hour or so.

My thinking was have it try restoring corrupted disks one bit at a time until it hit on a format that was valid.  I think the code to read the disk could be stripped out of MESS/VCC/XROAR or whatever and flipping bits in the dsk would be trivial.  You could even come up with a harness to just feed the bits directly to the Coco ROM to speed things up.

Anyway, the challenge would be knowing what was correct, and not just valid.  One case of many would be this:
Imagine a < character was corrupt on the disk (or BNE for you ML types)
The fuzzer subs in a > (or BLS)
The disk is now valid, and can be read
But the behavior would not be correct

Checksums would help, but I have no memory of what would be available, if anything, at this point.

Anyway, just thinking out loud.

-----Original Message-----
From: Coco [mailto:coco-bounces at maltedmedia.com] On Behalf Of Brian Goers
Sent: Tuesday, February 17, 2015 8:12 PM
To: CoCoList for Color Computer Enthusiasts
Subject: Re: [Coco] Rainbow on disk RAID

On 2/17/2015 2:16 PM, John Guin wrote:
So what is BOINC?
A search of acronyms did not give me a answer.


>
> With today's hardware, even if there were billions of possible 
>sectors, I can't see that presenting too much of a challenge.  Heck, 
>now that I think about it, this could be a project for BOINC or similar
> - "Help try combinations of values to restore old floppy media for legacy computers."
>
> Of course, validation correctness would be a problem.
>
> John
>
> -----Original Message-----
> From: Coco [mailto:coco-bounces at maltedmedia.com] On Behalf Of Melanie 
> and John Mark Mobley
> Sent: Tuesday, February 17, 2015 11:36 AM
> To: coco at maltedmedia.com
> Subject: [Coco] Rainbow on disk RAID
>
> Key
> RoD (Rainbow on Disk)
> RADE (Redundant Array of Independent disks)
>
> Error recover of RoD.
>
> RoD RADE => If we had 3 copies of each disk then we could select the sectors that match 2 out of 3 or 3 out of 3 and recover any errors.
> If 2 out of 3 sectors match then use one of the  matching sectors.
>
> Then we can recover from disk errors.  There is hope that we can preserve this information even if the disk are starting to fail, but we need to act soon.
>
> John Mark Mobley
>
>
>
> --
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> Coco at maltedmedia.com
> https://pairlist5.pair.net/mailman/listinfo/coco
>


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  Brian Goers
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