Cloning an external HD for off site backup...

Discussion in 'Mac Basics and Help' started by gpspad, Apr 29, 2018.

  1. gpspad macrumors 6502a

    Joined:
    Feb 4, 2014
    #1
    I am looking for a way to keep an off site backup for multiple macs on a small home network.

    Right now I have an external HD on a mac mini running as a server. The external HD is partitioned to a volume for each mac, every night I have CCC backup to that volume. it works great, but I have no off site backup.

    If I get another external HD, can I create an exact copy of that external HD portions and all and store it off site?

    The multiple bootable volumes from CCC on the external drive seem to be tripping me up with this...
     
  2. Fishrrman macrumors P6

    Fishrrman

    Joined:
    Feb 20, 2009
    #2
    Just get a drive of sufficient capacity.
    Partition it as required.
    Use CCC to do a clone of each partition.
    Store offsite.

    There's nothing complicated about this.
    Just create the second backup as you created the first one.
    CCC doesn't care.
    It will create as many clones as you need.
     
  3. Weaselboy Moderator

    Weaselboy

    Staff Member

    Joined:
    Jan 23, 2005
    Location:
    California
    #3
    You could just use CCC to clone external #1 to external #2, but if it were me, I would just use CCC to make two clone drives then alternate swapping them between home and work (or wherever your second, offsite storage location is).
     
  4. gpspad thread starter macrumors 6502a

    Joined:
    Feb 4, 2014
    #4
    That was my original plan, just take one drive out, and put one drive in. The problem is I don't know how to have CCC make an exact copy of the external drive with all the sub-drives in it.

    How do you do that, all I seem to be able to select is the smaller bootable drives, I want to all of it in one shot. that is what I can't figure out how to do....
     
  5. Weaselboy Moderator

    Weaselboy

    Staff Member

    Joined:
    Jan 23, 2005
    Location:
    California
    #5
    I don't think you can. You would need to make one CCC "task" for each volume, but that should not be a problem.
     
  6. chown33 macrumors 604

    Joined:
    Aug 9, 2009
    Location:
    Sailing beyond the sunset
    #6
    If you really and truly want to do that, then you'l have to restructure your current external drive.

    Instead of partitioning the external drive, you would have to erase it to a single partition that covers the entire drive, then make disk-images on the now bigger single partition, one for each Mac you intend to backup. You should use sparse-bundle disk-image format for the disk-images.

    So you'd go from a structure like this:
    External Drive:
    Partition for Mac A
    Partition for Mac B
    Partition for Mac C​

    to a structure like this:
    External Drive:
    Single Partition
    Disk-image for Mac A
    Disk-image for Mac B
    Disk-image for Mac C​
    If you understand the difference between a partition and a disk-image, then this should make sense to you. If not, then I recommend that you DON'T DO IT. It's a risky undertaking if you don't fully understand what's happening, or how to make, modify, or manage disk-images. You'd be risking all your future backups for very little gain.

    If you DO make disk-images, then it's a simple matter to use CCC to copy the disk-images themselves to another external drive. They should be unmounted at the time, i.e. not opened or attached. Again, if you understand disk-images, this should be plain to see.


    I'll be pretty busy for the next few days, otherwise I'd offer more explanation.
     
  7. gpspad thread starter macrumors 6502a

    Joined:
    Feb 4, 2014
    #7
    Thanks for the reply. I had thought of making a disk image to a NAS drive and then just copying them.

    I am guess I just use CCC to convert a disk image to a external drive if I ever have to. Unless I am missing something else I have to do?

    The main problem right now its all automated and relatively quick. The time I tried making an image on the NAS drive over the network it took a while, even over ethernet. Probably because the backups only copy the things that have changed, and the images are doing it all from scratch at a slower transfer rate.
     
  8. chown33 macrumors 604

    Joined:
    Aug 9, 2009
    Location:
    Sailing beyond the sunset
    #8
    It's not a "convert", it's a copy. That is, you mount the disk-image and copy it (using CCC) wherever you want. The original disk-image remains as it was, where it was.


    The speed of a NAS device depends on two main factors: the speed of the NAS itself, and the speed of its network connection. A very fast NAS can be quite slow when connected to a slow network. The NAS can't go faster than its network connection.

    "Ethernet" by itself is no guarantee of high speed. You have to look at the entire pathway between the NAS and the device using it. That includes cables. If you use the wrong cables (or even just one cable segment), then the entire pathway will only be as fast as the slowest segment. You must also use Ethernet switches, router, etc. that are sufficiently fast. And of course, the NAS itself must be fast enough, using whatever network protocol you've chosen (SMB or AFP/IP).

    Any backup's speed will also be constrained by what was copied previously. If you start a new disk-image from scratch, it will probably take at least as long as if you backup to a completely empty partition from scratch. There may be some variation, but I wouldn't expect a lot of difference.

    After the first backup to a disk-image, subsequent backups will be faster, because less data is being written.

    Since you haven't provided any details for any of your devices or network configuration, the above comments are general at best. You also didn't mention how your current partitioned external drive is connected, so it's impossible to guess how fast or slow it might be relative to a networked NAS.
     
  9. Fishrrman macrumors P6

    Fishrrman

    Joined:
    Feb 20, 2009
    #9
    OP:

    I recommend that you DON'T fool with disk images using CCC.
    That kind of defeats the entire purpose of CCC -- to create an instantly-finder-mountable easily-accessible copy of the source material.

    I agree with Weaselboy above.
    Just create a second backup from your "original source data".
    If there's more than one partition, you do more than one CCC job.
    One CCC clone for each partition.

    I do that myself. Multiple backups. Different partitions, different locations.
    Nuthin' to it.
     
  10. hobowankenobi, Apr 30, 2018
    Last edited: Apr 30, 2018

    hobowankenobi macrumors 6502a

    Joined:
    Aug 27, 2015
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    on the land line mr. smith.
    #10
    I have done this for years with other tools, and it has been flawless, and pretty fast. I'm would be surprised if CCC does not allow you to backup to image, and then update/append the image....rather than clone again from scratch. Chronosync does....although I like it less overall than CCC.

    I test on a regular basis, and the boot images have always restored correctly...no issues at all.

    You should also consider backing up the most precious, irreplaceable data the most often, like user home directories. Does not need be bootable. Bootable is grand, but there are downsides: space (lots of space, once you are talking about lots of volumes and/or partitions, time (especially with network backups), and complexity (both of backup and restore), and generally, you should not be using a machine while you clone it.

    I prefer a hybrid approach:

    1. Occasional bootable clones, especially before any changes or updates
    2. Daily, automated data backups to protect against data loss

    Another advantage of non-bootable backups is that you have even more tools to choose from, many of which will chug away in the background, not caring what the user is doing.
     

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