1. Microsoft Exchange Server creates a .pat file to record database page changes that the backup process runs while it is running. The above error can occur if it cannot access the .pat file for some reasons.

2. If the err_num is -1018, hardware issues are most likely to cause the problem.

3. If the err_num is -613, this indicates presence of checksum errors in .stm or SLV file. This problem can occur because of hardware issues or third-party SMTP disclaimer software packages.

Solution

You should troubleshoot the given problem by following these methods:

1. To unlock the .pat file, you need to stop the software that might be accessing the file, such as another backup software or an antivirus application. Alternatively, you can also wait till the application finishes and release the file. Try to run the backup program again.

2. In case of -1018 error, you need restore the database from last online backup or move the mailboxes to another store (in case you use Enterprise version) or run eseutil /p and isinteg -fix commands or run a third-party tool like Stellar Exchange Recovery software to recover exchange database.

3. In case of -613 error, you should repair the .edb and related .stm file.

If you execute eseutil utility, data loss is likely. Thus, using Exchange Mailbox Recovery is the safest option.

Stellar Exchange Server Recovery is a reliable utility that repairs corrupted Exchange database and allows restoring only the required mailboxes as *.pst files. This Exchange Database Recovery software supports MS Exchange Server 2007, 2003, 2000, and 5.5.It can also recover deleted mailboxes.