>I don't think there is any more need too bother with this train of
>thought. Thanks to the tips that Jerome gave this morning on how to
>create that dump, I was able to inspect the first 20 or so blocks, and I
>think I can safely say that the disk is a lost cause. Blocks 0-?? are
>totally toasted. I don't know how I managed it, but apparently I did
>something that caused the SYSGEN to write to there last night, it's got a
>binary image where there should be a directory structure. Sounds like
>the next time I try something like that I'd best turn the LA75 on as a
>console printer first so I can analyze what I did wrong :^/
It does sound like what I thought it was...
But remember, the disk may not be a total loss... many, if not most, of
the files are most likely still there (I'm expecting that sysgen simply
overwrote the beginning of the disk with each of the .OBJs... so the
amount of corruption would be no more than the largest .OBJ produced.
So, later directory segments would be okay, and there would be sufficient
info in them to recover those files. Earlier files would still exist,
following the directory... remember, they are contiguous files, so if
you find the start of one, you can get the whole file back.
There used to be a utility someone wrote, ndump, which looked at the
first n bytes of each block and reported on them... that way you could
figure out at least where your ascii text/source files were... and RT
provides commands which would allow you to grab just the blocks of the
disk needed to get a file...
It is possible, just procedural and time consuming... but if there is
information which is important enough, it is worth it...
>Thanks to your pointing out that the backup command is backup (Um, that
>was just a little to obvious) I'm now backing DU3: up, since I've got
>part of what was on DU2: on it. However, that still leaves me with a
>logical disk MACRO.DSK that I would like to recreate. With the directory
>toast, I guess that isn't easy. So.....
If you can find the beginning and end of the file... you can probably
restore it from the corrupted disk in its entirety...
Megan Gentry
Former RT-11 Developer
+--------------------------------+-------------------------------------+
| Megan Gentry, EMT/B, PP-ASEL | Internet (work): gentry!zk3.dec.com |
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Received on Thu Feb 04 1999 - 07:35:49 GMT