Q: How to ransfer time machine backups to a different formatted Hard Drive?

I believe Time Machine backups require a specific format drive. I guess if you do not want to format the drive that way then you can't use the backups on it anyway even if you could get them there.  Most new drives come formatted for use with Windows and are of a format (NTFS) that is petty much useless with Macs unless you are going to run special software (and which Time Machine still won't accept).

Backup disks you can use with Time Machine - Apple Support

You can move a TimeMachine backup to another hard drive but that drive must be formatted for the Mac. It cannot be formatted for Windows. If you want to use the drive for both the Mac and Windows and you want to use it for TimeMachine backups you have two choices: 1) partition the drive and use one partition for TimeMachine and the other for Windows. 2) format the drive for the Mac and install a utility on your Windows computer that will allow it to read the Mac disk format. There are several to choose from.

dwb wrote:

 

If you want to use the drive for both the Mac and Windows and you want to use it for TimeMachine backups you have two choices: 1) partition the drive and use one partition for TimeMachine and the other for Windows…

AFAIK, Apple discourages using a partitioned drive for Time Machine. Regardless of the partition scheme.

If you can point to documentation from Apple where this is discouraged I’d like to see it because it would add more ammunition to my argument against it. I know many techs don’t like the idea and even more don’t like the idea of a TimeMachine drive being used for other purposes - partitioned or not.

I’ve run into a number of instances where a user has partitioned a drive for TimeMachine and used the other partition for data - such as music or photos. So where’s the backup of this data, I ask? Oh, on TimeMachine is often the answer. So the data and backup are on the same hard drive? Now that’s a good reason not to partition a drive that will be used for TimeMachine. But is there a technical reason? I’m not aware of any at this time.

The most obvious answer is, partitioning it or using it for other purposes reduces the space available for backups. Another reason would be the extra disk access. I'm not aware if there are technical notes for you to peruse but certainly AppleCare techs discourage it.

I have always recommended against using a partitioned drive, it just shortens the time available before you have to deal with a full drive. Drives are cheap so unless your data is equally low in value, buy another drive for it.

dialabrain wrote:

 

The most obvious answer is, partitioning it or using it for other purposes reduces the space available for backups.

True but if the user has a 4TB external drive and a 512GB MBP based on my experience that drive would hold as many as 4 years of backup data. That’s over kill. Many people think I’m extreme for suggesting they use a TM drive that is 3-4 times the size of their data source!

Another reason would be the extra disk access.

Irrelevent. TM can back up to a server based drive (one of Apple’s scenarios in its TM knowledgebase article) and disk access for such use will be much greater than in a personal setting.

I'm not aware if there are technical notes for you to peruse but certainly AppleCare techs discourage it.

AppleCare techs encourage and discourage lots of things and as a tech with 30+ years of experience I’ve heard more than my share of nonsense which includes statements that directly contradict Apple knowledgebase articles so I don’t put much faith in what AppleCare techs say - certainly not level one or even level two techs. Unfortunately even the Apple Geniuses of today lack the experience and knowledge that they once had.

I’m not saying I disagree that it is a bad idea but until shown otherwise I think it is a bad idea for most people. Your first argument holds true in many but not all instances - reducing the space available for a backup - and my scenario of data being backed up to the same drive as it source is another good argument against the practice. But there are other instances where it might be reasonable and the OP has a case where it might be.

If you think back, I have too but the OP has a case where it might be reasonable, especially with a big enough drive.

dwb wrote:

 

If you think back, I have too but the OP has a case where it might be reasonable, especially with a big enough drive.

FWIW, it would be nice if you would make up your mind. In one sentence you say you discourage the practice and in another you say it might be reasonable. What one can do and what is "reasonable" is not the same.  It's no wonder new users can get confused.

I’ve made up my mind - it is reasonable if

the user makes an informed decision based on the fact that a TimeMachine’s backup destination should be large enough to hold the entire contents of the source drive(s) as well as its incremental backups (which will be hourly if the drive is connected to the computer full time) for a significant time before TM must delete older backups. A reasonable estimation of the TM drive is 3-4 times the size of the source data to be backed up.

In a perfect world users would dedicate a drive completely to TimeMachine and another for other purposes but we don’t live in a perfect world. Perhaps unlike you I work part time in a real world Apple store where many of our customers drive 5 year old cars and have a part time job not because it is fun, like I do, but because it lets them buy a few of the extras like a MBP instead of a Dell.

To be totally honest, I consider it a victory if I can convince a user that having a backup strategy and using it isn’t optional. Now how about we argue about something important like Adele vs Prince or Mets vs Yankees.

dwb wrote:

 

I’ve made up my mind - it is reasonable if

 

the user makes an informed decision based on the fact that a TimeMachine’s backup destination should be large enough to hold the entire contents of the source drive(s) as well as its incremental backups (which will be hourly if the drive is connected to the computer full time) for a significant time before TM must delete older backups. A reasonable estimation of the TM drive is 3-4 times the size of the source data to be backed up.

 

In a perfect world users would dedicate a drive completely to TimeMachine and another for other purposes but we don’t live in a perfect world. Perhaps unlike you I work part time in a real world Apple store where many of our customers drive 5 year old cars and have a part time job not because it is fun, like I do, but because it lets them buy a few of the extras like a MBP instead of a Dell.

 

To be totally honest, I consider it a victory if I can convince a user that having a backup strategy and using it isn’t optional. Now how about we argue about something important like Adele vs Prince or Mets vs Yankees.

Well, I'm happy for you that you've sorted it out for yourself. Keep up the good work.

dwb wrote:

 

If you think back, I have too but the OP has a case where it might be reasonable, especially with a big enough drive.

It will be the same, the time to full will be shorter, but with todays drives it may be enough. But if an error in the other partition takes down access to the drive it's a false economy. Buy an extra drive is my advice, always.