NTFS Change Journal Size

ntfs

How many file changes can be stored in an NTFS Change journal database with size 32MB for instance. How do I get from megabytes to amount of files?

Best Answer

The number of changes that a given USN journal file can hold can be estimated with the following formula:

journal size/((60 bytes + (length of file name)) * 2)

The number "2" in this formula stems from two journal entries for each file change: 1 for open and 1 for close. Divide the journal size by the size per change to determine the approximate number of changes that can occur before the journal wrap error is encountered. Assuming 8.3 filenames, this maps to approximately 200,000 files and/or directories for a 32 MB journal file. The number of changes would be less if long file names were used.