What Is Time Machine?
After you try out El Capitan and decide that you would like to switch back to your old OS—probably Yosemite—you will have to perform two procedures. First, you will have to erase El Capitan and then you will need to install your previous OS. Meanwhile, you will have to save your El Capitan data with the Time Machine. This will take some time, but it will enable you to complete the process successfully. So, Time Machine is your backup feature for X OS which is built into the system. It will enable you to keep copies of all files you want to save.
Part 1. How to Backup Data with Time Machine?
Time Machine can keep copies of all the files you want to save. In order to use it, you will first have to choose location for backup. There are several location options: an external hard drive which you can connect to FireWire, ThunderBolt portor USB to your Mac; an external hard drive which you can connect to AirPort Extreme 802.11ac with USB port; OS X Server on a network or an AirPort Time Capsule.
Time Machine can perform backups on an hourly basis, daily basis or weekly basis. After the backup drive becomes full, the system will automatically start deleting the oldest backups. Time Machine will ask you when you connect it to Mac weather you want to start using it to perform backup. You need to choose "Use as Backup Disk", and then select the encrypting option if you want to protect your files from being accessed by other users.
It might seem that the first backup lasts ages because you have lots of files on a startup. However, you can continue working on the Mac while Time Machine is backing up. Time Machine will notify you once it completes that first backup or if it encounters problems during the process. After you perform your first backup, Time Machine will backup files automatically whenever there are any changes since the previous backup. Time Machine will perform this automatic backup every time it is connected with Mac, even if you have the Power Nap feature.
You can use AirPort Time Capsule with Time Machine. If you choose to use AirPort Time Capsule as a Time Machine backup feature, you will first have to set it up. Just check its instructions on how to use it in network. When you configure it, you can select the option to use it as your backup Time Machine. Here are the steps to follow:
From the options you will get, choose the "AirPort Time Capsule", which you are going to use as backup.
Part 2. How to Restore Mac OS X El Capitan from Time Machine Backup?
So, once you have backed up your El Capitan data on a Time Machine, you can uninstall El Capitan, which will erase it from your computer. After you erase El Capitan, you can again install your previous OS. If that was Yosemite, follow these steps:
Attach the Yosemite installer and hold down the Option key. Soon an icon stating "Install OS X Yosemite" will appear, and you need to click it.
After this, OS X Utilities window will show, and you should choose "Disk Utility” and then “Continue.”
After the Utility app starts, choose the hard drive of your Mac in the left column (it’s the first one listed). Click on the "Erase" tab and name the hard drive in the window that will appear, choosing one of the OS X Extended formats.
Part 3. How to Recover Data from El Capitan Before Overwriting It?
The iSkysoft Data Recovery for Mac enables four different recovery options for the easy and safe recovery of lost data. They will enable you to recover all different types of files, such as: photos, documents, video, emails, music, etc. You can recover not only documents but also photos, video, music, email, archive files, and more.Four different recovery options for the easy and safe recovery:
- Lost Data Recovery - It enables you to recover data you lost because you deleted it by accident and emptied the Trash or maybe because files were corrupted.
- Raw Recovery - This will enable a more detailed scan, recovering files by their signature. In this raw recovery mode, you can recover more than 45 different file types, such as JPG, PNG, M4V, MOV, MP3, M4A, zip files, emails, etc. The only problem with this recovery mode is that you will not be able to get the original names of the files and folders.
- Partition Recovery - This is an option designed to retrieve all data lost due to deletion, formatting, resizing, or any Partition related case.
- Resume Recovery - This mode enables you to save your scan results to perform data recovery later.
Simple Steps for Recover Files with Recoverit (IS):
Step 1. Choose a Recovery Mode
After you have opened the program, you need to choose a recovery mode. For exammple, you can choose "Lost Data Recovery" which enables you to recover the data you lost because you deleted it by accident and emptied the Trash.
Step 2. Scan Files
After that, you will get a window where you will choose your drive from the list. If you want to recover everything, click on "All Files" and then continue to click on "Scan" icon to start searching for lost files. If you don't see the drive where you lost the files, refresh the window and it should show up on the list.