Backing up two drives to one

Discussion in 'macOS' started by macstatic, Mar 1, 2009.

  1. macstatic macrumors 6502a

    Joined:
    Oct 21, 2005
    #1
    What backup solutions are available for backing up two drives on to one backup drive without causing any confusion?

    My setup consists of:
    - Powerbook (80 GB)
    - external Firewire drive (160 GB)
    - external Firewire drive (500 GB) for backup

    I'm running MacOS 10.4.11, so please don't suggest Time Machine ;)
     
  2. sickmacdoc macrumors 68020

    sickmacdoc

    Joined:
    Jun 14, 2008
    Location:
    New Hampshire
    #2
    Partition the external disk into two partitions and use Carbon Copy Cloner or SuperDuper to clone each of the others to its own partition. Simple and dependable!
     
  3. macstatic thread starter macrumors 6502a

    Joined:
    Oct 21, 2005
    #3
    How would I go about to set that up in a way to make it simple and easy?
    And what about rotating backups? Or would it just continue to write new backups until the backup drive is full (meaning I would have to do some "housecleaning" now and then; removing old backups)?
     
  4. sickmacdoc macrumors 68020

    sickmacdoc

    Joined:
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    Location:
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    #4
    Since you won't be using TM, clones done with CCC or SD will not "grow" beyond the amount of data on your internal drives. Clones are in essence just a duplicate (or snapshot) of the drive you are backing up at the moment it time you are backing it up.

    As you re-run the clone program you will do what is called "incremental backups" in which it makes sure your clone on the external is up date with changes you have made on your internal drives. By that, I mean that it removes files from the clone that you have deleted on your internal, it will add new files that you have added to your internal and will replace files that you have modified.

    As I mentioned the easiest way to clone to a single external from two Macs is just to format the external disk into two partitions and identify them by name- like the first partition being called My iMac Backup and the second being called My MacBook Backup or some such plan.

    Then when you run the clone program on Computer A you select it as the source and the appropriate partition for that Mac as the "Target" or "Destination" drive. Then connect the external to Computer B and do the same thing, selecting its appropriate partition as the destination.
     
  5. ElectricSheep macrumors 6502

    ElectricSheep

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    Feb 18, 2004
    Location:
    Wilmington, DE
    #5
    If you want to preserve history, consider using a GUI front-end to rsync, such as Backuplist+. Rsync allows you to run in an incremental backup mode, where it will only copy files that have changed between backups and maintain an up-to-date snapshot of the information you wish to have backed up. Files that are deleted or modified between backups can be moved into a dated directory, so that in the event that you accidentally delete or alter a file you can still have the option of recovering it.

    Its not quite as fancy as Time Machine, as Mac OS X 10.4 does not support directory hard links, but its capable enough to give you peace of mind from both physical disaster, and user error.
     
  6. macstatic thread starter macrumors 6502a

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    Oct 21, 2005
    #6
    I'm not sure I understand because I tried CCC out a while back, first creating a clone, then later doing an incremental backup, and I believe I was presented a new folder (with that day's date as its name) which I thought was the new files since my clone backup.
    What I want to know is if the backup drive will receive unlimited numbers of those dated folders (with their contents), or if after a while the oldest such folder will be deleted, creating a backup "rotation?
     
  7. cinder macrumors member

    Joined:
    Jun 26, 2004
    Location:
    Seattle
    #7
    So TimeMachine WILL allow you to back up an internal drive and an external drive to a second external backup drive?

    I want to do the same thing, but I DO have Leopard.
     
  8. sickmacdoc macrumors 68020

    sickmacdoc

    Joined:
    Jun 14, 2008
    Location:
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    #8
    The current version of CCC (at least since 3.0 for sure) lets you choose whether or not you want to keep changed and deleted files in folders like you describe when CCC performs the incremental backup on the clone itself. This is controlled by your choice in the checkbox in the main screen under "Backup options" called "Archive modified and deleted items".

    It will not delete the oldest of these Archive folders (as opposed to TM) so if you choose to use the option eventually you would need to trash the oldest of them manually.
     
  9. sickmacdoc macrumors 68020

    sickmacdoc

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    #9
    CCC has the same ability that you have described (if you choose to archive changes) if the option to "Archive modified and deleted items" is selected in the "Backup Options" section.
     
  10. sickmacdoc macrumors 68020

    sickmacdoc

    Joined:
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    #10
    Yes, TM will allow you to back up any number of hard drives (whether internal or external) to a single backup drive. It keeps the individual drive's backups in individual folders.
     
  11. macstatic thread starter macrumors 6502a

    Joined:
    Oct 21, 2005
    #11
    I guess I can live with having to manually delete old backup folders. And since the folders are named with the dates it should be very quick and easy.

    For backing up my two drives though, would it be possible to back up the external Firewire drive (which only contains files, no operating system like my Powerbook of course, which means I really don't need to clone that specific drive) to a folder on the backup drive, or do I have to partition my backup drive into two?
    The reason I ask is because this might result in a lot of wasted space, depending on how much new stuff I write/change on the Powerbook or the external drive, while a single partition would leave equally much space for either backed up drive. Besides, I've already cloned my entire Powerbook drive (and then copied the contents of the external drive on to a folder on the backup drive simply by dragging the files over in the Finder).
    In other words: would it be possible to back up the following on to my (single partition) external backup drive:
    a) Powerbook 80GB drive (cloned first, then incremental backups)
    b) external Firewire drive (copy all files first, then incremental backups)

    I'm not sure if you've already answered this or not (in case I haven't quite understood), but is there a way I can do the incremental stuff for both drives easily, without having to remember a complicated procedure?
    Something like clicking on a script or whatever.
     
  12. sickmacdoc macrumors 68020

    sickmacdoc

    Joined:
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    Location:
    New Hampshire
    #12
    OK, well yes you could both backups onto one partition- BUT (there had to be a but right?) but that would complicate the backup procedure which I see later in your post would probably not fit well with your desire to simplify it.

    Since a clone is by definition a 100% duplicate of a drive, a single partition with a cloned drive and then other backup files added to it is no longer a clone. When the clone was updated by the incremental update process, it would want to remove the "other files" on that drive since they would not represent anything currently on the drive being cloned. There are options within CCC anyways to tell it not to remove files from the backup drive that don't exist on the source drive when doing an incremental update, but then items that had been removed from the source drive would not be removed from the clone either, so it would no longer be a true clone.:(

    SO- the only way around this with a single partition is to use another option in CCC to "clone to a folder" on the backup drive which would work ok but takes away the ability to boot from the clone in case of a failure of the original disk which is a great advantage of having a true clone in the first place!

    So what it comes down to in the interest of the simplicity you desire is to make a guess as to which backup would be most likely to grow the largest over time and make two partitions with those relative sizes.

    With that, cloning the first time as well as doing incremental updates could not be much simpler-- simply start CCC, choose the drive you wish to clone in a pull down menu under "Source" then select the appropriate partition under "Target" and click "Clone". When that is complete, select the other drive under "Source" and its appropriate partition under "Target" and press "Clone" again. Job done!

    In case I have misunderstood the number of external drives you have (it seems to me that you have two) then most of the above would be invalid. I am assuming you have one drive specifically set aside for backups as would be recommended (since it could be removed in between clones to isolate it from the system for safety).

    Sorry this is so darn long- but it is far easier to know how this stuff works than to explain it many times!;)
     
  13. macstatic thread starter macrumors 6502a

    Joined:
    Oct 21, 2005
    #13
    Yes, I have two external hard drives (both with Firewire 800/USB 2 interfaces: I use Firewire of course).
    One drive (500 GB) is the one I'll be using for backups, the other drive (160 GB) is used for storing photos.
    I'd like to back up both the "photos" hard drive as well as my Powerbook's internal drive (80 GB) on to that 500 GB drive.


    It seems to me that cloning the two drives (or one of them, and copying the other) makes the system very flexible and easy to restore in case of an emergency, but also more cumbersome to use each time when backing up, and also could end up using lots of valuable space on one backup partition while the other partition has lots of free space.

    If I could make a system where backing up is simply a matter of clicking on an icon in the dock or something like that I would be happy.
    The easier it is to use the more likelihood is that I regularly back up my data. If it becomes too hard and too many details to remember I'll probably put aside backing up regularly.

    So, if my intention of cloning the Powerbook is to back up everything on the drive first and foremost, and not to be able to boot from it things should be a lot easier, right?
    I'm still a little confused as to what I should do. Just shows that I'm not used to backing up my stuff ;) :eek:
     

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