Backing uop with Time Machine

Hey ** we're now a 2 iMac couple, both Senior Citizens! I have 2 1TB external drives and use them alternately to back up. Is there a way to back up both Macs to one drive? If not can I alternate the external drives between the 2 iMacs or are they dedicated?

Generally it's a good idea to dedicate one drive to Time Machine. However, if you have enough space on the single drive, you could partition it and dedicate one partition to each iMac.

So, since your iMacs have a 500GB drive each and you have 2 1TB externals, theoretically you could use the Partition tab in Disk Utility to split one of the drives into 2 500GB partitions. That should be enough to give you a decent backup and allow you to share it between the two machines.

Partitioning external hard drives.

cwa107 said:

Generally it's a good idea to dedicate one drive to Time Machine. However, if you have enough space on the single drive, you could partition it and dedicate one partition to each iMac.

So, since your iMacs have a 500GB drive each and you have 2 1TB externals, theoretically you could use the Partition tab in Disk Utility to split one of the drives into 2 500GB partitions. That should be enough to give you a decent backup and allow you to share it between the two machines.

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Thanks; I've done one and will try it out before doing the other one.

Backing up 2 Macs to Time Machine

cwa107 said:

Generally it's a good idea to dedicate one drive to Time Machine. However, if you have enough space on the single drive, you could partition it and dedicate one partition to each iMac.

So, since your iMacs have a 500GB drive each and you have 2 1TB externals, theoretically you could use the Partition tab in Disk Utility to split one of the drives into 2 500GB partitions. That should be enough to give you a decent backup and allow you to share it between the two machines.

Click to expand...

I did as you said but have since been told by Applecare that you can back up 2 Macs to the same Time Machine. This seems to me a more satisfactory solution as one Mac may use up more capacity than another.

For anybody else thinking of doing this you do of course have to eject from one Mac and connect to the next. If you have 2 external hard drives (I label them 1 & 2) you also have to go to System Preferences on the dock and click on Time Machine to get the option to choose the disk to use; otherwise it doesn't know that it's the current Time Machine. Don't try going staright to Time Machine on the dock as that takes you into the Time Machine 'universe'.

Alwyn said:

I did as you said but have since been told by Applecare that you can back up 2 Macs to the same Time Machine. This seems to me a more satisfactory solution as one Mac may use up more capacity than another.

For anybody else thinking of doing this you do of course have to eject from one Mac and connect to the next. If you have 2 external hard drives (I label them 1 & 2) you also have to go to System Preferences on the dock and click on Time Machine to get the option to choose the disk to use; otherwise it doesn't know that it's the current Time Machine. Don't try going staright to Time Machine on the dock as that takes you into the Time Machine 'universe'.

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That's interesting. Are you sure they said 'Time Machine' and not 'Time Capsule'?

De-partitioned external drives 'test drive'

cwa107 said:

That's interesting. Are you sure they said 'Time Machine' and not 'Time Capsule'?

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Yes and I've de-partitioned both drives and test-driven one of them. From Finder/Time Machine/Backups/ it shows the 2 iMacs by name. Clicking on Time Machine in Applications will only show the iMac to which Time Machine is connected.

I have several questions:
I have a 500 GB can I use a 500 gb external drive w/time machine - is that "big" enough?
If the worst happened and I lost everything, how do I get everything back from the external drive if my computer has crashed?

Thanks for all the info.

SweetPea

SweetPea said:

I have several questions:
I have a 500 GB can I use a 500 gb external drive w/time machine - is that "big" enough?

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Yes, but your "backup history" will not go "back in time" as far back as it would if you had a larger drive. I have a 500GB drive but only use about 400GB of it so my matching 500GB backup drive goes back only a few months.

If the worst happened and I lost everything, how do I get everything back from the external drive if my computer has crashed?

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You first replace the crashed drive with a new drive. After that the answer differs depending on whether you were running Lion or not.

For pre-Lion: you would boot the machine from the system DVD you got with your original purchase, re-install the OS. At some point it will ask if you want to do a restore from Time Machine. You do. That will restore everything exactly back to the place it was when the last TM backup was performed.

For Lion: you start up the machine and wait for the Internet Recovery to appear. This will reinstall Lion via the internet. At some point it will ask if you want to do a restore from Time Machine. You do.