Is Apple’s Time Machine A Space Age Space Hog?

I suggest anyone reading this article pay close attention to Jeff’s style of use and how it may differ from their own. Those of you who have considered the style of many Mac applications probably realise that half of why they are good is the features they leave out. Naturally this sometimes makes them less suitable for certain users, but generally it is a Good Thing. Time Machine is meant to address the issue that most users do not make regular backups. Those that it doesn’t apply to will generally be advanced and interested enough to tailor their own backup system using existing 3rd party applications or their own scripts.

I haven’t recently verified this, but I believe a number of points in this article are either misleading or simply incorrect:
o The highlighted, bold statement that “Time Machine backs up every single file… whether I like it or not” remains, with just a discreet edit and the comments referring to the fact that isn’t true.
o There is a strong suggestion that one needs to read the help to work out how to exclude files or folders. I suggest users look for it themselves before believing this.
o Time Machine backups are stored as simple files on the backup disk. It is false that “Time Machine does not allow me to go into the hard drive where the backup data is stored to delete the files and recapture the storage space.”
o “Of course, I can always erase the drive each time it fills and start all over again, but that seems like a tremendous waste of time.” It is particularly a waste of time since you’d just be doing a more brutal implementation of what Time Machine already does; delete old backups.
o “In this case, it may delete files I would rather keep, in order to keep files I’d like to delete.” Indeed, no telepathic artificial intelligence included. It warns you that it’s about to delete some old backups, then does so. This is the preferred course of action for most users, and even picky users so long as they have set up appropriate exclusions.

In general, Time Machine’s backup strategy is very close to what a large proportion of advanced, rsync-based setups do. It doesn’t let you fine tune some things, but gives enough control such that only people with very specific usage patterns are disadvantaged. Even people such as Jeff should generally be able to establish a suitable setup, and for those who cannot there is still an abundance of alternatives.

Jan… I agree with almost everything you just said. If I had emailed Mike before writing this post, it certainly would have looked different. I don’t like deleting posts. I considered editing this post in a major way to address some of the innacuracies, but decided to put them in the comments instead. As you can see at the end of the post, I clearly wondered if I was missing something obvious.

That said, the casual user may not find the help items that would explain why a straight implementation would appear to make the drive fill up faster than it needs too.

I believe I have set up workable solution via excluding they key folders where my workflow starts. I fully intend on posting a follow up to this review when I can see how Time Machine decides what to delete as the disk gets closer to full.

Jan, your comments are extremely accurate, except for the ability to delete files from the Time Machine hard drive. While it is true they are simple files, I have tried many times to delete them. Each time I get this message: “The operation can’t be completed because backup items can’t be modified.”

Again, I may be missing something. So, if you know a workaround for this, I’d love to hear it.

True about deleting files through the Finder, my mistake. I haven’t identified how to tweak things so they can be, but it is possible through the Terminal. Superuser access makes it easy, but the following method is both safer and can be done by non-administrators.

Please note that performing the following steps is done at your own risk. I do not describe the intricacies involved in employing these steps widely or in some less common situations. I also have not yet tried this on a release version of Leopard.
1) Navigate to a folder in the backup containing files you wish to delete, using the `cd’ command.
2) Both the folder and files will have access control lists (ACLs) stopping you from immediately deleting the files. These need to be removed. If we want to delete the file `bob’ and are happy to remove all ACLs, then:
- Remove the current folder’s ACL with `chmod -N .’ (that `.’ is important)
- Remove the ACL from `bob’ with `chmod -N bob’
3) With the ACLs removed, we can delete `bob’ using the `rm’ command:
`rm bob’

My rudimentary tests show that Time Machine had no problem with me doing this, but I cannot guarantee this.

If there’s interest then it should be straightforward for someone to write an application which lets people do this through drag & drop rather than the Terminal.

Jan… thank you. When I get back home to my Leopard test machine, I’ll give it a try. I know I’ve got at least 10 gig of stuff that I don’t want on there!

A better way to delete all the files for a backup is to simply open up Time Machine for the folder in question and find the file or files you want to zap.

Select them. then click on the “Tool” icon in the toolbar and select “Delete All Backups of myfile.txt”.

Time Machine will then do its thing, deleting the files and reclaiming the space.

A much better solution than fiddling with hard links via Terminal.

Michael… if it had been a snake it would have bit me on the ass several times!

THANK YOU!

That’s the ticket. And this review needs to be rewritten.

You could:

1) create a folder where you always put those big uncompressed videos

2) tell time machine to exclude that folder