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thetruth1985

macrumors 6502
Original poster
Sep 17, 2010
371
4
Does that mean that I need a 6tb disk? Right now, I have a 1tb hard drive in my iMac. I am looking at many different options of expanding storage but one of the cheapest options is to simply add a 2 or 3 tb hard drive to the iMac via usb. I am currently using a 2tb hard drive for time machine backups but everything I read suggests that my time machine drive will not work if it is not double the size of the original drive(s). So does this mean that if my iMac + usb drive = 3tb, I would need a time machine disk of 6tb? If so, is buying a NAS the only option for this solution since there are no 6tb drives?
 
No, there is no rule that your TM backup needs to be 2X the space you are trying to backup. The additional space will really determine how far back your incremental backups will go. The big factor will be how much your data changes. I personally don't have all of my data backed up (for instance not all purchased music / tv shows, since I can now re-download it and I occasionally back this stuff up on bare HDs that I keep off-site).

For your specific case, if you really do think you will be backing up 3+ TB of data you may want a 4TB TM drive (of course you will have to go with some kind of RAID since 4TB drives are kinda rare these days :p ) and that should be plenty for all your data plus plenty of extra room for incrementals. If you then use up the 4TB, TM will just remove the oldest backups to make room for newer data changes.
 
No, there is no rule that your TM backup needs to be 2X the space you are trying to backup. The additional space will really determine how far back your incremental backups will go. The big factor will be how much your data changes. I personally don't have all of my data backed up (for instance not all purchased music / tv shows, since I can now re-download it and I occasionally back this stuff up on bare HDs that I keep off-site).

For your specific case, if you really do think you will be backing up 3+ TB of data you may want a 4TB TM drive (of course you will have to go with some kind of RAID since 4TB drives are kinda rare these days :p ) and that should be plenty for all your data plus plenty of extra room for incrementals. If you then use up the 4TB, TM will just remove the oldest backups to make room for newer data changes.


This pretty much explains it! Thanks a lot!
 
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