CrashPlan and the Mac library folder

gistfile1.txt

This file seeks to explain what should and should not be backed up from the Library folder on your Mac to minimize the amount of data sent over the wire to your backup server. Some files in the Library folder are important to backup whereas others are not critical. 

There are two general strategies for handling the Library folder:

1. Start with nothing (de-select the Library folder) and selectively add files/folders
2. Start with everything and de-select files/folders we do not want to back up

Regardless of strategy, here are some things that you SHOULD back up and things you SHOULD NOT back up. Note, the exclusion list includes folders outside the Library folder that should also not be backed up.

GOOD TO BACK UP
~/Library/Keychains/ - Keychain data and settings
~/Library/Mail/V2 - Mail data and settings
~/Library/Application Support/AddressBook - Contacts data and settings
~/Library/Calendars/ - Calendar data and settings
~/Library/Safari/ - Safari data and settings
~/Library/Fonts/ - Fonts
~/Library/StickiesDatabase - Stickies
~/Library/Preferences/ - Other preferences

DO NOT BACK UP
~/.dropbox - Contains files Dropbox uses to authenticate and identify you. Just re-authenticate if needed.

~/Dropbox/.dropbox.cache - Deletes from your Dropbox will move files here first for a while, so no need to back up files you intended to delete.

~/Library/Developer - This folder contains a lot of documentation and build artifacts. 

~/Library/Application Support/DogeCoin - In this folder, do not back up the blk*.dat files. This is the DogeCoin blockchain, which is large and changes frequently. Other files in this folder SHOULD be backed up. 

~/Library/Application Support/Steam - Downloaded Steam games go here, and these can be re-downloaded from Steam servers if needed. 

~/Library/Application Support/VMWare Fusion - This folder contains metadata and snapshots of your virtual machines (not the actual virtual machine container files). 

~/Library/Mobile Documents - Cache of iCloud documents. There are stored on the cloud already.

~/Library/Application Support/Blizzard - Replay and save files from Blizzard games. 

~/Library/Application Support/Google - Hefty caches and snapshots for Google products that do not need to be backed up.

~/Library/Application Support/iLifeAssetManagement/assets - This contains photos downloaded if you have Photo Stream turned on. Again, on the cloud; no need to back up.

~/Library/Containers - Apps can use this folder to store data. For example, when Mail downloads an attachment, it stores the copy in here.

~/Library/Logs - App logs that do not need to be backed up.

~/Library/Mail - Metadata and caches for the Mail app.

~/Library/Mail Downloads - Downloads from the Mail app.

If you use Chrome you do want to back up parts of ~/Library/Application Support/Google -- if you want to back up your bookmarks, settings, currently open tabs, etc. Similar to how you have suggested backing up ~/Library/Safari/.

CrashPlan automatically filters out Chrome's browser cache, which is the main big thing from that folder that you don't want to back up. In addition I've found it helpful to manually exclude these smaller caches because they change frequently and just cause a lot of churn:

• ~/Library/Application Support/Google/Chrome/CertificateRevocation
• ~/Library/Application Support/Google/Chrome/CertificateTransparency
• ~/Library/Application Support/Google/Chrome/Default/Network Action Predictor
• ~/Library/Application Support/Google/Chrome/Default/Network Action Predictor-journal