Time Machine - Omitting File

Discussion in 'macOS' started by speekez, Dec 29, 2010.

  1. speekez macrumors 6502

    Nov 19, 2003
    Quick question. Just trying to understand how Time Machine works. I have it set to do backups automatically.


    1. I create and save test document to desktop. I initiate a manual backup.
    2. I delete file from desktop.
    3. I verify that time machine shows file was backed up.
    4. I do not restore the file from the backup to the desktop
    5. A day or so later the backups for that day are compressed to a singular daily backup for the day rather than hourly.
    6. The file from the desktop is no longer available in the backup.

    Is this because the test file was no longer on the desktop for the last hourly backup of that day? Does a "daily backup" reflect a snapshot of the content of the computer at the end of that day -- which would mean if you create a new file during the day and unknowingly delete the file before end of day (24 hours), Time Machine will not have captured it for its daily backup?

    Thanks for clarification
  2. mstrze macrumors 68000

    Nov 6, 2009
    Hmm...that's an oddly particular situation.

    I would assume that the daily backup is what exists on your computer at the end of the day, assuming things that you have tossed and NOT recovered within the span of a day were not files that were worthwhile to you. Or maybe it is based on how long the file existed? Since it would have only been in one hourly backup, it was deemed as a throwaway file?

    One might assume TM should archive the greater of the files on a machine, but then you would be archiving a ton of temporary files and the like so perhaps this is a way of filtering out unneeded files...i.e. anything that exists less than an hour AND does NOT exist at the end of the day.

    I hadn't even thought about the lack of hourly backups prior to the current day.

Share This Page