Time Machine: what does it mean in practice?

[dogbone]

If all deleted or overwriten files can be retrieved then that means they are not really deleted. So what does that mean in terms of storage space.

Do you need a 10 terabyte drive to run it? What about 200mb photoshop files, does TM keep storing them over and over day after day?

 

[iBookG4user]

I assume that time machine does a full backup and then only does incremental backups after that.

 

[dogbone]

What does that mean in practice though.

Like say you have a 200mb photoshop file on the go. So that is backed up, but are you then saying that if a change is made to it that TM only backs up the changed bit? I can't see how this is possible without a second complete iterated 200mb file.

 

[crackpip]

I am guessing that it not only does incremental backups, but when it discovers a file has been changed it only records the changes. This is how it works in Subversion, even for binary files. Thus if you have a 200MB photoshop file, yes it will take up an extra 200MB, but if you then make 20MB of changes. It will only take up 220MB (+metadata) and you will have a backup of both versions.

crackpip

 

[Kaioshin]

Why does everyone assume it needs a big hard drive to work? Wasn't it specifically stated that the backups are created on a second/external disk, or even a server (.mac...?)... I assume it can also easily be turned off, or made to monitor only certain types of files (or to a certain size).

 

[virus1]

i only see it being practical in documents or small files, not in large graphic or video files. otherwise, like said, takes up too much space. does it really backup so many copies of the video file? sometimes there can be video files over 20GB, and if those are deleted for the sake of space, it makes that completely useless, because it doesn't actually delete it.

 

[jsw]

The Time Machine FAQ should address most of these issues, so, to consolidate discussion, I'll close this thread and ask people to move to that thread. I won't merge threads because I think it'd just be confusing.

If you feel there's a compelling reason to re-open this, please PM me.