[LU-13951] How to get the timestamp of a file data_version's last change

• Type: Improvement
• Resolution: Unresolved
• Priority: Minor
• Affects Version/s: Lustre 2.12.5
• Environment: CentOS 7.6
• Assignee: Peter Jones
• Reporter: Stephane Thiell

Description

Hello! On Fir storage, we're tracking time when a file's content was last modified. Not the mtime, but the effective time when the file's content had changed. Indeed, we prefer not to rely on the file's mtime which is easily modified by touch.

To mitigate this, we currently record files' data_version in Robinhood DB along with a timestamp (max of ctime and mtime). Our purge policy is based on data_version, and if it hasn't changed for 3 months, that means the content has not changed and we purge the file. While this solution works for us, it's not lightweight and it would be easier for us if Lustre could make the last time data_version was updated in Lustre accessible via the liblustreapi.

I don't know how difficult it would be to implement this feature, but this is something that could be useful. Thanks!