Question About Time Machine

[Sdahe]

Hello,

I have an iMac with a HD of 1TB of capacity.. just got an external HD with 1TB of capacity too for Time Machine only. My question is this... how good is Time Machine for backups?... Will Time Machine eat my external drive with unnecessary files?

Thanks for the help

 

[benwiggy]

Define "unnecessary".

First off, TM copies over your entire drive contents. Then, every hour, it copies only those files that have changed since the initial copy. It then continues to do that.
The clever thing is that it presents to the user all the files on the disk in each snapshot: essentially, every unchanged file is a link (like an alias) to the last time it was changed.

It keeps hourly backups for the past 24 hours, daily backups for the past month, and weekly backups until your backup drive is full.
http://support.apple.com/kb/ht1427

It allows you to restore any file from any point in time that it as a record for. Or you can restore the whole disk. While other backup strategies may offer other features, it is a very useful, default, automated, "point and forget" backup system.

Ideally, you want a backup drive that is 2 to 3 times your data. You can of course exclude some folders from the entire backup if you wish.

 

[Sdahe]

Define "unnecessary".

First off, TM copies over your entire drive contents. Then, every hour, it copies only those files that have changed since the initial copy. It then continues to do that.
The clever thing is that it presents to the user all the files on the disk in each snapshot: essentially, every unchanged file is a link (like an alias) to the last time it was changed.

It keeps hourly backups for the past 24 hours, daily backups for the past month, and weekly backups until your backup drive is full.
http://support.apple.com/kb/ht1427

It allows you to restore any file from any point in time that it as a record for. Or you can restore the whole disk. While other backup strategies may offer other features, it is a very useful, default, automated, "point and forget" backup system.

Ideally, you want a backup drive that is 2 to 3 times your data. You can of course exclude some folders from the entire backup if you wish.

Thanks...

unnecessary - temp files like in windows...

 

[benwiggy]

Temp files and caches are not included.

 

[Sdahe]

Temp files and caches are not included.

Perfect... thanks!!!

 

[gnurf]

I just back up most of my home folder. Good candidates for exclusion are Steam folders and any media files. I would rather have a manual copy of music, for instance, since it's not a constantly changing bunch of data. The system is quickly reinstalled if it breaks, anyway.

TimeMachineEditor and BackupLoupe are two tools I can recommend if you want more control over your backups.

 

[benwiggy]

I would rather have a manual copy of music, for instance, since it's not a constantly changing bunch of data.

If it doesn't change, Time Machine will make one copy, and then not back it up again. It's part of one automated strategy, and will get backed up if changes are made. You can restore files easily through the TM app.

What advantage does a manual backup have?

The benefit of backing up the system is -- say you "accidentally" delete the Mail app, you can restore it without having to reinstall the entire OS.

TimeMachineEditor and BackupLoupe are two tools I can recommend if you want more control over your backups.

My advice is not to tinker with Time Machine. Most instances of TM going wrong that I've seen are from people not using it as it was designed to be used.

 

[gnurf]

What advantage does a manual backup have?

Not having to put the music backup on the same volume as a Time Machine backup is an advantage for me.

My current TM backup has some of /Users/<me>/ plus /Applications. The iTunes library's index is on the system drive, but the music is on a different drive. I'm basically only backing up the things which are somewhat important and change frequently - all the music is recoverable in other ways

My advice is not to tinker with Time Machine. Most instances of TM going wrong that I've seen are from people not using it as it was designed to be used.

TME changes scheduling. There is nothing wrong with that. Much of my changing stuff is source code. I have the local repository, a server copy, the server's remote backup and the TM daily snapshot. I don't need hourly backups of something which changes THAT frequently.