Good folders to exclude from Time Machine backups
Time Machine is a really effective tool for backing up everything on your drive. And when I say everything, I mean it — Time Machine indiscriminately backs up a lot of junk on your drive. And because of the techniques it uses and the way some files are used by your apps, you might find that your 500GB external backup drive is getting full after just a few months of use.
It’s really easy to identify folders for exclusion from Time Machine, which will save time and space during backups. It’s worth noting, though, that if your machine’s drive does fail, you won’t be able to execute a full restore without having some of these locations backed up. Then again, if you’re anything like me, you’re far more likely to just do a full reinstall and just restore your lost user data. (Doing a full restore from backup just doesn’t have many advantages compared to a full system reinstall, anyway.)
These are just a few suggestions — you should NEVER exclude anything from backup if you’re unsure you have another copy, aren’t able to get it again, or are unaware of the possible ramifications. Of course, you’ve got any good folders you think should be added to the list, feel free to drop ‘em in comments.
Obvious
The duh stuff.
- /Applications - This will likely save you more space than any other single folder, especially if you have lots of apps. Just make sure you know what programs you’d want to get back if your machine were to die.
Caches and downloads
Big directories of files that should probably be excluded automatically, but aren’t. Unless you’re a crazy developer debugging code, you’ll probably never need a backup of your caches.
- /Users/[user]/Library/Caches and /Library/Caches - Between the two you can knock off a few hundred megs of constantly changing, essentially useless data.
- /Users/[user]/Downloads - Where all your internet downloads wind up. Frequently changes, and if you’re anything like me, it’s filled with gigs of garbage.
- /Users/[user]/.Trash and /.Trashes - Some people might see value in backing up their trashed files. Not I.
More after the break.
Audio and media
Some more obvious picks. You probably don’t need to back this stuff up.
- /Library/Audio - You can save from the hundreds of megs to gigs here. Keep an eye out for the GarageBand samples, they weigh a ton.
- /Users/[user]/Music/iTunes/iTunes Music/Podcasts - I don’t really re-listen to podcasts, but even if I did, they can be re-downloaded easily. So the 3GB+ I save here is a no brainer.
Time Machine un-friendly apps
The data produced by some of these apps can easily be the worst offenders when it comes to backups. Until they get their act together, they should likely be excluded categorically.
- Parallels (/Users/[user]/Library/Parallels) and VMware (/Users/[user]/Documents/Virtual Machines)- You’ll definitely want to keep a copy of your virtual machines, but if left included in Time Machine backups, your system will continuously save the virtual disks each time you use Parallels or VMware. (VMware has become a little more TM-aware though, which is good.) That means potentially hundreds of wasted GB — not to mention tons of lost time during backup.
- Entourage (/Users/[user]/Documents/Microsoft User Data/Office 2008 Identities) - Same deal here, Entourage uses one giant, constantly changing file to store all your mail. It sucks not to have your email backed up though, so be sure to use something other than Time Machine for keeping a copy handy in case of emergency.
- /Users/[user]/Library/Mail Downloads - Whenever you open an attachment in Mail, it stores a copy of the file in your Mail.app attachments folder. If you’re a heavy Mail user, excluding this will save you some real space.
System
Beware! You likely won’t screw up anything by excluding this stuff, but if you run into trouble these are some pretty important folders. Note: you’ll need to hit “show invisible items” to exclude some of these.
- /usr, /sbin, /private, /bin - Collectively contain about a billion essential system files that can ultimately just be reinstalled in case of disaster.
- /system - Root system folder. Contains lots of essential stuff — gigs of it, in fact. Great place to save space.
Yeah, I need to exclude my virtual machines from incremental backups. And I want to partition my USB drive so both Mac (Time Machine) and PC (Acronis) can write to it… hope that’s possible via AEBS.
Comment by Dave Zatz — Friday, May 23, 2008 @ 10:16 am
When I ran Parallels, I let TM back it up. Little did I know that when I restored my machine, I would have to reinstall Parallels - and I could not for the life of me find my CD. I wasn’t all that happy with Parallels anyway, so it was a good excuse to move to VMWare.
I do backup my entire drive. I know it’s not space efficient. I did once do a TM restore of everything. It actually showed a lot of performance increase anyway, as TM already doesn’t backup some system files. But for everyone else, these seem like great suggestions!
Comment by John B. — Friday, May 23, 2008 @ 10:37 am
Entourage:
User > [User] > Documents > Microsoft User Data > Office 2008 Identities
Comment by Jamie — Friday, May 23, 2008 @ 10:45 am
VMWare defaults to /Users/[user]/Documents/Virtual Machines/
I like having Time Machine backup my VM disks, it’s like having a disk image of Windows made every hour.
I hope Apple adds disk image backups to Time Machine in the future (like Windows Vista’s Complete PC Backup) as currently to go from dead hard drive to fully working Mac needs a lot more work then a disk image.
Comment by James Carey — Friday, May 23, 2008 @ 10:52 am
Great post. I agree to add the Entourage/Office identities.
Comment by Brent — Friday, May 23, 2008 @ 10:52 am
Jamie and James, thanks!
Comment by Ryan Block — Friday, May 23, 2008 @ 11:09 am
@Jamie-
Careful there! Don’t you want to back up your email? There’s a database inside that folder that holds all your messages, not just useless cache and preferences.
Comment by CosaMostro — Friday, May 23, 2008 @ 11:32 am
I’m going to agree with our benevolent dictator Steve’s desicion to backup everything. Excluding files from Time Machine seems to defeat the purpose of what the program is designed to do - store all your backups easily in once place and to restore to exactly the way you had it. It would seem very unapple like to have a backup solution that required you to reinstall all your applications, restore your mail from a different location, and still have to possibly reinstall the OS. Those who want to finely tune what user data is backuped up are much more likely to already have a backup solution. I appreciate the article but would like more cred giving for why the vast majority of users should just let Time Machine do what its going to do.
Comment by Nathan — Friday, May 23, 2008 @ 11:56 am
Sometimes Time Machine backups simply take up too much space, which really sucks. When Leopard first launched, Aperture wasn’t compatible and Apple recommended you exclude your Aperture data files from backups — clearly they understand its limitations as a backup system. People aren’t going to just buy drive after drive to make sure they have 100 revisions of their virtual machines saved.
Comment by Ryan Block — Friday, May 23, 2008 @ 12:01 pm
@Ryan Thanks for the quick reply.
I was unaware that Apple recommended that particular data be excluded. (Steve you make me sad) Still, I would argue that the problem is - if you have alot of data your going to need alot of space to back it up. I still agree with the idea of time machine as a simple all encompassing backup solution. I don’t believe that its a good solution, especially for non power users, to just backup less data. But this would be a discussion of if you should exclude data not what you should exclude, which was more the point of your article.
Comment by Nathan — Friday, May 23, 2008 @ 1:11 pm
@Cosa
That’s kind of the whole point. Entourage backs up your email as a single file, so ANY activity within Entourage means a whole new backup in Time Machine.
My Entourage file is several gigs and to be writing that to disk every single hour is going to quickly run your external hard drive out of space.
So instead of leave as much mail as possible on my Exchange server and back the file up manually every week or so.
Comment by Jamie — Friday, May 23, 2008 @ 1:20 pm
Interesting list. For most users, excluding the mail databases and ~/Library/Caches should be plenty — the /Applications tree is going to be mostly static for a conventional Mac user.
Comment by Mike — Friday, May 23, 2008 @ 4:59 pm
Very nice. I’ll have to revisit this when I pickup my Mac gear.
Comment by Jesse — Tuesday, May 27, 2008 @ 3:54 pm
~/Library/Caches is already excluded (have a look at /System/Library/CoreServices/backupd.bundle/Contents/Resources/StdExclusions.plist)
Comment by Tim — Wednesday, May 28, 2008 @ 2:59 pm
You can also exclude alot of invisible items that your installed applications place in your home directory you never knew were there. I’m assuming many of these user specific files are things you could easily set up again if anything terrible ever happened.
I would suggest if there is a specific program that has the capability to export user settings (ie. ArchiCAD exports/imports xml user settings) that you utilize your customization settings and DO backup the folder that contains them.
Go to your Home Folder (Command Shift H)
Click on the “Show invisible items” so that it’s checked and then
Select all (Command A) then
Deselect the folders that are important to you (Command Click)
User settings in XML format not only take up less space, but are handy when trying to standardize multiple computers.
(High 5!)
Comment by RYAN SINGER — Wednesday, May 28, 2008 @ 5:09 pm
Oh, and if you have EyeTV (and you should. It’s awesome), exclude the recordings folder. As awesome as I just exclaimed EyeTV to be, the recordings are massive. They’re MPEG-2, so it takes like 700MB for a half hour show. And then there’s the LiveTV buffer for when you pause it.
Not good for Time Machine. It sort of bleeds storage capacity.
Comment by Karl — Thursday, June 5, 2008 @ 11:04 am
Very interesting tips. Particularly the cache files.
However, I was wondering about the frequency of changes of some of these files. Obviously, the Microsoft User Data for Entourage will change daily if not hourly causing a potential huge backup every hour on the hour due to the way the data base is created.
I would hope if I backed up my system files once that they would not need backing up again for a while until an Apple update was issued. Same with hopefully most applications.
Comment by Bill Alford — Thursday, June 12, 2008 @ 10:39 pm
I am wondering if it shouldn’t be the reverse, i.e.
tell time machine to “include” specific folders (data) and not backup anything else. If the HDD gets hosed, i ‘ll reinstall from scratch. The only thing i cant reinstall is my personal data.
How does time-machine gen its backup list ? Is it an exclude or an include ?
Comment by Ali — Saturday, June 21, 2008 @ 5:35 pm
[...] Just about everything Ryan Block suggests [...]
Pingback by Tuning Time Machine | Stephen Foskett, Pack Rat — Saturday, July 12, 2008 @ 9:00 am
Man, can’t thank you enough for the tips. Backing up 32GB+ data everytime I touched parallels was making me going crazy. Keep up the good work mate.
Comment by Shakil — Sunday, July 13, 2008 @ 11:30 am
Excellent tips Ryan! It’s weird, I just got my Mac and decided Time Machine would be useful, but I couldn’t make up my mind on what to back up. I started haphazardly googling for pointers, assuming I wouldn’t find anything concise…but lo and behold! :)
Comment by Aashay — Tuesday, July 15, 2008 @ 9:34 pm
Removing the caches made the thing! I saved almost 1 GB of space.
Thank you, mate!
Comment by DJ N-4ceR — Saturday, August 9, 2008 @ 12:16 am