Any reason to backup the 'library' or 'applications' folders?

[DramaLLama]

Applications folder I pretty much think not since they can all be re-downloaded through the 'previous purchases' through the app store (except for maybe a few) but is there any reason to be backing up the 'library' folder?

 

[Nermal]

Library contains email (if you're not using a "stay on server" protocol such as IMAP) and generally I do keep a backup of it just in case.

 

[Bear]

Applications folder I pretty much think not since they can all be re-downloaded through the 'previous purchases' through the app store (except for maybe a few) but is there any reason to be backing up the 'library' folder?

If an application becomes unavailable on the app store, you won't be able to re-download it.

You didn't say which Library folder, but there are preferences files there, depending on which one, data files as well. Also, any fonts you've installed, browser plugins, bookmarks, etc. So skipping the library folders can lose data if you need to do a restore.

I use Time Machine and when I needed to restore my system after a drive failure all I had to do was start up the Time Machine restore and walk away. When it was done restoring my system was ready to go, no need to fiddle with downloading stuff. My point here is that without a full backup, having to restore your system will take a lot more time and require more user intervention to get it correct.

 

[Nermal]

If an application becomes unavailable on the app store, you won't be able to re-download it.

Have you actually experienced this? The game "Neverwinter Nights 2" is no longer available but I can still redownload it from my Purchases list. Have you run into a situation where that's not the case?

Inconsistency is fun! 🙂

 

[Bear]

Have you actually experienced this? The game "Neverwinter Nights 2" is no longer available but I can still redownload it from my Purchases list. Have you run into a situation where that's not the case?

Inconsistency is fun! 🙂

I was kind of presuming that the Mac App Store did the same thing as the iOS App Store.

 

[benwiggy]

You will find plenty of posts here from people who "accidentally" deleted Mail, or TextEdit, or similar. Easy to restore from a backup; not so easy to reinstall otherwise.

The /Library folder contains lots of stuff.
Application Support has lots of files that installers put there. Fonts are there. Services and other workflows are there. LaunchAgents are there. System Preferences are there.
In short: yes, back it up.

The size of the backup required is small compared to the benefit.

 

[DramaLLama]

OP here, I use CrashPlan for backup online as well as backing up to a external hard drive locally...

In the 'library' folder is there anything that would be constantly updating that would be getting uploaded to CrashPlan backup online? Maybe "appdata" in the library folder? The size of it all doesn't matter to me but the constant file changes might get annoying.. Basically what should I OMIT if anything from the library folder.

And what about the 'app' folder what's the verdict on that? I see through the app store everything is downloadable but would that even be possible to install again if I backed up the 'app' folder via CrashPlan?

 

[talmy]

If an application becomes unavailable on the app store, you won't be able to re-download it.

Have you actually experienced this?

It's happened to me. The iLife software has undergone upgrades such that it no longer runs under Snow Leopard. I wanted to redownload a purchased (under Snow Leopard) copy of iMovie and couldn't do so.

Always back up applications purchased from the Mac App Store! This was a response I got on this question to Apple:

I understand you are concerned about the app, iMovie, that you are no longer able to update because it now requires Lion. As an owner of a computer with the Tiger OS (two systems before Leopard) I can certainly understand that this is inconvenient to have to update your computer before updating your apps but I would like to help you out in any way I can.

Thomas, developers frequently release updates and newer releases of their software to correct known issues and allow customers access to newer features. Apple is not response for the loss of any purchases or the loss of the ability to update an older app version. We encourage customers to back up their hard disks regularly. If an item needs to be replaced, you can restore your purchases from the backup and avoid the need to purchase replacement copies of titles from your collection. That is why we strongly recommend customers back up their purchases on a regular basis.

In my case I luckily still had an old copy in a TimeMachine backup that I could copy to the Snow Leopard system.

 

[Nermal]

It's happened to me. The iLife software has undergone upgrades such that it no longer runs under Snow Leopard. I wanted to redownload a purchased (under Snow Leopard) copy of iMovie and couldn't do so.

Ooh, thanks for that; I'd forgotten about upgrades potentially breaking things or become incompatible. That's a very good point so I'll add the Applications folder to my backups (it helps that I've just upgraded my TM drive from 750 GB to 2 TB so I should have the space now!)