OS 10.10 upgrade - Time machine

[arncalars]

I have searched this topic without finding answer.

I'm using Time machine with external drive ( G-mobile 1TB ) as backup on my iMac late 2013 with Mavericks.
Do I need to format external backup drive when OS 10.10 is available or can Time machine handle files from Mavericks and new OS on the same drive.

Regards Lars

 

[AaronM5670]

As it's not out yet, nobody knows for sure but what's likely is that it will use the same (HFS+) file format, so it will be fine - if not I'm sure Apple will come up with something to enable a transfer of files. When I upgraded from Snow Leopard to Lion to Mountain Lion to Mavericks etc. everything on my Time Capsule was fine - I really don't see Apple changing anything this time around, you'll be fine!

 

[maflynn]

You'll be fine, it will be backward compatible so there will not be a need to reformat the drive.

 

[arncalars]

Thank you - nice to know.

But, wouldn't it take up more disk space on external drive when Time machine back up two OS systems ?

I think - if I start with empty back up drive with new OS, assuming everything is fine after upgrade, I would use back up drive most efficiently.

 

[maflynn]

Depending on how much free space you have, it may delete the old back up.

 

[Weaselboy]

Thank you - nice to know.

But, wouldn't it take up more disk space on external drive when Time machine back up two OS systems ?

I think - if I start with empty back up drive with new OS, assuming everything is fine after upgrade, I would use back up drive most efficiently.

Yes... that first backup after you install 10.10 will be huge, because it needs to backup all the changes. What I usually do is just let that complete and use the machine with the new OS for a month or so, then I erase the Time Machine disk and start a fresh backup with the new OS. You do not have to do this though, as like maflynn said, TM will eventually purge off the old data.

 

[mmomega]

I have searched this topic without finding answer.

I'm using Time machine with external drive ( G-mobile 1TB ) as backup on my iMac late 2013 with Mavericks.
Do I need to format external backup drive when OS 10.10 is available or can Time machine handle files from Mavericks and new OS on the same drive.

Regards Lars

You will know the answers within a week about beta upgrades + Time Machineat least.
If 10.10 is anything like Mavericks or any beta upgrade, the release notes usually mention if a specific build is compatible with earlier versions of Time Machine backups.
Always read your release notes. Especially, if you are worried about upgrade problems and in that case I would definitely not upgrade my main machine without knowing for sure.
In my case, my Mini server is where all of my files are housed and it doesn't get upgraded until I know FOR SURE there are no problems. My iMac and MBA are my test beds and daily drivers that can be formatted in an hour or less is something drastic happens.

 

[arncalars]

Thanks for useful comments.

 

[arncalars]

Yes... that first backup after you install 10.10 will be huge, because it needs to backup all the changes. What I usually do is just let that complete and use the machine with the new OS for a month or so, then I erase the Time Machine disk and start a fresh backup with the new OS. You do not have to do this though, as like maflynn said, TM will eventually purge off the old data.

Even though my G-mobile backup drive is almost new and only 7% full, I'll go for your suggestion and erase when upgrade is safe.