CompuServe Messages

The bad links shown by DiskSalv aren't due to the blocks possibly having been used previously. I'm not sure if this reflects a bug in the DiskSalv program, but its possible that it does. I haven't found this consistant enough to pin down, though the program does seem to resolve such problems correctly. The first pass of DiskSalv scans every entry on the disk, and reports the contents. Here's where a previously used block might be reported as "Data" instead of "Unused". The second pass of the program is the part that looks at links, and it bases these links on file blocks that it has read. Disk blocks are chained in order, and the entire list of blocks used in a file are present in the file header and the extension headers, if required. DiskSalv looks at both pointers for any "next block" assessment; if they don't match, it looks at both blocks, and checks various things, like the sequence numbers, the parent blocks, and if each has previously been tagged as being part of a valid file. This is where a link mismatch is likely to be reported, though the chance of choosing the wrong link at this point seems very unlikely.