When performing a TM wireless backup, a sparsebundle with a name based on the machine being backed up is created, but if you rename that sparsebundle, it is still used for the backup. What would I need to do to preserve that backup and start a new one on the same drive (connected to an Airport Extreme)?
"Time Machine can’t back up to an external disk that's connected to an AirPort Extreme..."
If you've installed some sort of hack to make this happen, you're on your own. Don't count on being able to restore your data when you need to.
Hmm... Well, all I did is plug a USB drive into my Airport Extreme and then select it from the Time Machine menu. In fact, that procedure is described here as being supported for over 3 years:
http://www.macworld.com/article/132613/2008/03/airporttime.html
But... that wasn't my question. 😉
The official Apple documentation, which was last updated a couple of months ago, explicitly says that it's not supported.
OK, based on this I agree with you:
http://support.apple.com/kb/HT2038
Let me rephrase my question, then: When TM is backing up wirelessly to a drive, it creates sparsebundles. How is a given sparsebundle designated to be the backup of a given machine? It does not appear to be by name. Is a MAC address stored somewhere? Thank you.
The only documentation I know of is the tmutil(8) man page, which says this:
Machine directories and sparsebundles are owned by one computer
at a time, and are tracked by unique identifiers rather than com-
puter name, host name, or ethernet address. The inheritbackup
verb reassigns the identity of the specified item, reconfiguring
it so the current host recognizes it during backups. When inher-
iting a sparsebundle, the machine directory within will also be
claimed.
OK, so it sounds like there is no offically supported way for a given hard drive or partition to have more than one TM sparsebundle backup for a given machine?
Nothing prevents you from creating more than one partition on the same physical device, and using each of those partitions alternately to back up the same machine. I don't know why you'd want to do that, since it makes no sense, but you could. I hope you're not making the mistake of confusing Time Machine with an archiving system. It isn't one, and if you try to use it that way you'll inevitably come to grief.
Unless I am misremembering, there used to be (or still is) a long thread describing the benefits of having a separate partition for each TM sparsebundle; by the user Ponzi, I believe. I appreciate you trying to protect me by steering me away from using TM as an archiving system, but I don't use it that way (I use CCC and a separate FW drive stored off site). But, thank you (sincerely) anyway. 😉
My question is this: Let's say I have a Foo drive, my computer is Bar, and I have a TM Bar's.sparsebundle on that drive. I want to leave that backup alone, rename it to Bar's Old.sparsebundle, and have TM start over with a new Bar's.sparsebundle on that same Foo drive. I want to be able to access both of the TM backups for recovery reasons. Is there an officlal way to do this? From what I can see there is not, because all you get to do when you set up TM is point it to a drive, and when I tried renaming the sparsebundle manually, TM still used it.
Let's say I have a Foo drive, my computer is Bar, and I have a TM Bar's.sparsebundle on that drive. I want to leave that backup alone, rename it to Bar's Old.sparsebundle, and have TM start over with a new Bar's.sparsebundle on that same Foo drive. I want to be able to access both of the TM backups for recovery reasons. Is there an officlal way to do this?
If you're qualified to use the shell, you can do that sort of thing with tmutil. See its manual page. Otherwise, no.
Props. Respect.
How is a Time Machine sparsebundle associated with a machine?
