Very Computer

I am having a major Hard drive problem. I am using a motorola 8260
(PPC603core) and the following problem was seen when chkdsk is run on
the hard drive.

"/main/Ai" has illegal start cluster
"/main/Ai" file larger than its chain of clusters Entry will be
deleted.

"/main - lost chains" cross-linked with another chain
"/main - lost chains" cross-linked with another chain
"/main - lost chains" cross-linked with another chain

this last message repeats over and over. If the system is rebooted and
chkdsk is run again, the "/main - lost chains" cross-linked with
another chain message is all that is displayed and continues to
displayed over and over (for the last 15 hours).

As far as I can tell (after checking extensively) there never was a
file named Ai on the /main partition and no one had any files open in
write mode on the /main partition.

I need to know how this corruption can occur. I do know what the error
means, but this corruption should not occur if there were no files
open when the power was recycled or the machine was reset. It almost
appears as if every cluster on the /main partition is corrupted, the
FAT is definited screwed.

Does anyone know of any solutions to this problem. KNown causes?? Has
anyone seen this problem before????

Any help or info would be greatly appreciated.

Thanx in advance.

Shanan

This sympthom suggests that you have got a problem with the
hard disk block driver, the file system is getting bogus data from
the disk, or fails to write any data to the disk, or both.

The file system code is taking a rather naive approach towards
the block driver and all the interface circuity, assuming they
perform its commands perfectly. If that is not the case, hell breaks
loose, as it did for you.

What I would suggest to do in this situation, is take one step
at a time, run a series of tests on the hard disk block driver.
There are many things that could be wrong, but most frequently
the psoblems have to do with DMA and Cache coherency.

Then of course you can mount the file system on a RAM drive,
in order to test the file system code without the hard disk interface
and driver.

Lastly, some time ago I have informed this newsgroup about a bug
in PowerPC version of DosFs2.0, arising from the PowerPC use of
floating point registers when generating 64-bit integer arithmetic.
See the group archives.

Hope this helps,
- Leonid Rosenboim