Memory mapped files and new CBT-based file backup

1

I have noticed in the Windows CBT client change log that from v2.1.14 there is support for using changed block information for incremental file backups. Does it also mean that UrBackup client for Windows is now able to detect all changed files including files changed through memory map?

We have data storage engine that uses memory-mapped files to store data. Windows OS does not change last modification time file attribute if the file was written to through memory map. Standard UrBackup client seems to use this attribute to determine which files have changed because it ignores these files completely during incremental backup. If the new version with support for CBT file backup used information about changed blocks to determine which files have changed instead of last modification time attribute it should probably backup memory mapped files as well.

Thanks for answer and great work on UrBackup and the CBT driver.

2

No, it uses the USN number and tracks open files. I have even blogged about this Can you use the last modified file time on Windows as change indicator for incremental file backups? | UrBackup Developer Blog . So if it doesn’t work in your case for some reason, we should track that down.

3

You are right, it works fine. I had only a few incremental backups with minimal changes completed and I did not properly interpret the file version list in web UI. After more backups and a few tests it all became clear and it works perfectly.

Thanks for help, have a great day.
M.