HP Data Protector Software Performance White Paper

Figure 40 shows the default configuration parameters for filesystems. Use of the native

Filesystem Change Log Provider is set OFF.

Figure 40. Backup configuration – default filesystem options – use Change Log Provider

A file tree walk can take a considerable amount of time, especially when the directory structure

is large and contains millions of files. The Windows NTFS Change Log Provider, based on the

Windows Change Journal, addresses this issue by querying the Change Journal for a list of

changed files rather than performing a file tree walk. The Change Journal reliably detects and

records all changes made to the files and directories on an NTFS volume, which enables Data

Protector to use the Change Journal as a tracking mechanism to generate a list of files that

have been modified since the last backup. This is very beneficial for the environments with large

file systems, where only a small percentage of files change between backups. In this case, the

process of determining changed files completes in a much shorter period of time.