> My *.llb files seem to overwritten with garbage, and become unreadable
> in LabVIEW. I first noticed this with version 5.3.1 and decided to
> upgrade to 6.0.2. This fixed the problem for a while, but now my
> entire vi.lib directory has been damaged (all .llb files under vi.lib
> are unreadable). The file size appears to be the unchanged, but it is
> unreadable. I've opened one of these files and noticed that there
> were some random text messages leading me to believe that they are
> overwritten with random sections of memory. Anyone seen anything like
> this before? This is extremely frustrating.
This file corruption used to happen frequently on Windows 3. It happens
less with the VFAT file system, and it seems very rare on NTFS. Each
file is really com
posed of some number of blocks. The blocks are
scattered over the disk and as files move/grow, the file system will add
and delete blocks from the list for the file. If this list of blocks
ever becomes scrambled, then the file contents will be scrambled with
the contents of other files.
Either before or after deleting the mangled LV from your disk, be sure
to run a disk repair utility. It will scan looking for and fixing block
lists that don't make sense and many other file system problems. If
this happens often, you may want to start a routine of running the disk
repair every couple weeks. Once the disk data structures have a
problem, it tends to lead to other problems. Occasional repair keeps it
from causing bigger problems. Also, if you do find problems frequently,
you may want to look for the root cause. Does the power go out often,
does the computer crash often. These are the normal mechanisms for the
file system to get out of whack. You might also want to consider movi
ng
to NTFS if you are running NT or 2000.
Greg McKaskle
