#Disk layout
This weekend, I got the dread "Corrupt Disk" requester as I tried to take a
directory on a hard disk partition. I used Sectorama, and found three bad
pointers, which I zeroed out. One pointer was in the root directory, the
other two were in a directory that hadn't been accessed in several days. In
each case, the pointer was to a "Data/Corrupt" type sector; however, it was
a copy of what should have been good data. I could jump to the parent of
the corrupt sector, and find the proper header to the (text) file, which I
could then trace through, data-sector by data-sector, without encountering
the bad sector.
So, I can now use the partition. My questions are: Were these bad pointers
likely corrupt versions of good pointers that had been there previously? I
can't tell if any files are missing, but it doesn't seem like it. Why did
only those pointers, and not the rest of the data in the sector (or for
that matter, the track or entire partition) go bad? Why were there bad
pointers in the header sector to a directory that had been OK after the
last write to it? Or are these just mysteries that mankind was not meant
to comprehend? On a related theme, how can you tell which sector is the
root directory? Is it the first sector of the middle track (on which
head?)? And, how is free space monitored and allocated? What is the format
of the sectors with the free map? Where is this info published, if
anywhere? Thanks in advance /Mike