On Thu, Feb 10, 2022 at 09:49:14PM -0800, Kenneth Porter wrote: >--On Thursday, February 10, 2022 11:08 PM -0500 Jon LaBadie ><jcu at labadie.us> wrote: > >> Are you reading that as "atime gets updated every 24 hrs"? If so you >> are missing "if needed". I.e. if the file's data blocks have been read. >> >> Checking time-stamps and sizes are not operations that cause atime >> updates. Those are inode operations, not data reads. > >That I got. I was concerned with the case where rsync does a checksum to >verify that the file's contents didn't change without changing the >timestamp. > Which you indicated are "less frequent" for full backups. How often are full backups done? And no, it would not be a write for each file. It would be an update to the in memory version of the inode. At some point it will be written back to "disk". But only as a block of many inodes for many files. Some of those files may not even have had any timestamp changes. Others might require that the block of inodes be written because there was an mtime, ctime, size, permission change in any one of the inodes in the block. But it would be one write for all the inodes in that block. -- Jon H. LaBadie jcu at labadie.us