A clone is what it sounds like, an exact copy of your drive, so you can use it as a boot drive if the situation warrants it. Time Machine is nice because it keeps multiple versions of your documents, but it takes longer to restore from a Time Machine backup.
Encryption: Third-party and FileVault
Disable any third-party full-disk encryption software you are running. If a problem occurs during the El Capitan upgrade with the third-party encryption, you might not be able to access your data. after your El Capitan upgrade is complete, check with the software developer about El Capitan compatibility before your re-activate the encryption.
If you are upgrading from Snow Leopard and you’re using FileVault, you should disable FileVault before upgrading. When you’re done upgrading, you can start using FileVault 2, which is an improvement over FileVault.
Next up: El Capitan installation
Preparation is everything, and these tips will help make for a smooth upgrade to El Capitan. Fortunately, performing a standard upgrade is easy.
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