Time Machine HDD space requirement.

Discussion in 'macOS' started by reddevil0728, Jun 22, 2010.

  1. reddevil0728 macrumors regular

    Joined:
    Jun 19, 2010
    #1
    May I know if lets say the size of my MBP's HDD is 500gb, must i get a bigger hdd just so time machine can work or i can just get another 500gb?

    reason for asking is because, due to those computer calculation etc, the external harddisk maybe a couple of mbs smaller than that of the internet harddisk.
     
  2. brad.c macrumors 68020

    brad.c

    Joined:
    Aug 23, 2004
    Location:
    50.813669°, -2.474796°
    #2
    Having more space on the back-up allows Time Machine to store older archives than a single snapshot of your drive. In other words, older or deleted files can be recovered from further back. If that is important to you, get a larger backup HDD than what your computer currently has.

    If you're trying to limp by with an existing HDD that is the same size, you can choose to select folders to ignore. I do this with folders that contain movies/swap files/large files that change often, and I don't care to maintain. In my case, I only back-up 120 GB of the current 180 GB on my laptop.
     
  3. Penn Jennings macrumors 6502

    Joined:
    Apr 22, 2010
    Location:
    Michigan
    #3
    I'm not a TM expert but keep this in mind: if you have a 500 GB drive, the 500 GB TM will be "OK" while you only use 150 GB AND you aren't making major file modifications frequently. Once your 500 GB drive gets full, your TM will allow you to restore your system but will not have the ability to go very far back in time.

    I have a 500 GB drive, I use a dedicated 2 TB via Firewire 800. I have used 840 GB and that lets me go back to April (Purchase date). I probably over did it LOL. However, I wanted to make sure that a year from now I can still restore back to a like new configuration.

    By the way, although FW 800 is more money, I got it because if I have to restore I didn't want to wait 8 hours with USB 2.0. FW 800 is more than twice as fast as USB 2.0.
     
  4. Penn Jennings macrumors 6502

    Joined:
    Apr 22, 2010
    Location:
    Michigan
    #4
    Remember, TM keeps:

    • Every hour for the last 24 hours.
    • Every Day for the last month.
    • Every week after the last Month until it runs out of space.

    TM primarily stores the delta of whats changed. It doesn't make a full backup very often. If you make every small changes, your TM disk will go a long way back.

    If you make large changes frequently, the hourly and daily backups will kill your weekly backups.

    Sooo, how far back do you want to go?

    I hope that all helps
     
  5. reddevil0728 thread starter macrumors regular

    Joined:
    Jun 19, 2010
    #5
    Is it possible to remove older entries from the time machine when it is full?
     
  6. Penn Jennings macrumors 6502

    Joined:
    Apr 22, 2010
    Location:
    Michigan
    #6
    Time machine will auto-magically remove older backups as needed. You don't have to do anything yourself. It would probably be bad if you tried.
     

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