Error -521 –
the resolution depends on the actual cause. If anti-virus software is
running on the server, do a comprehensive and exhaustive check on which
subfolders the software is running against and remove the Exchange databases,
log files, and check files and remove the M: drive from the scan. If you
are using 3rd Party backup software, attempt a backup with NT Exchange-aware
backup. If it succeeds, check with your vendor for any patches,
updates, or fixes for your software.
Error -612 –
Check the Application log carefully for related events and patterns
that may relate to this event. Check the System log carefully for related
events and patterns including any errors related to hardware, drives,
controllers, or the file system. If there are any such errors, replace the
hardware, update the hardware system files, or repair the file system to
prevent any future errors. If the information store database is running,
it is suggested that you ExMerge your data to .pst files. You then may
be able to stop the information store. If the database is consistent
with Eseutil /MH, you can then remove all the log files and check file, start
the information store, and perform a successful online backup.