Time Machine backups
Don’t back out of backing up – it’s so easy to set up
Having run through all the previous potential fixes, if your Mac is still running slowly, you’ll need to take
more drastic steps. While your Mac may be experiencing hardware failure, if it is still functioning, however slowly, it’s more likely the problem has to do with your system software. If this is the case, try to run a backup of your Mac before doing anything else.
Time Machine
Your Mac has a built-in app for running backups named Time Machine. Time Machine makes daily backups of your data which it can then save either to an external hard drive or to an AirPort Time Capsule. The latter can create a fast wireless network and are useful for backing up several Macs, but an external USB hard drive is the simplest and cheapest option.
The first time you connect an external hard drive, macOS will ask if you wish to use the drive for backing up. Click Use as Backup Disk to have Time Machine automatically format the drive to be compatible with your Mac and begin transferring files. This process will erase any data already on the drive, so try to have a dedicated one just for backing up. The capacity of the drive should be at least equal to the hard drive inside your Mac. For instance, if you have a 500GB hard drive in your Mac, use a 1TB external drive for backups.
All the data on your Mac will be backed up. You can go to System Preferences’ Time Machine pane to view the status of your backups at any time.
From here you can click ‘Show Time Machine in Menu Bar’ to display a Time Machine icon at the top right of the screen. Click this once to quickly view the status of backups. If you have already been using Time Machine, click this and choose Backup Now before proceeding further.
System Restore
Time Machine performs a complete initial backup, and subsequently keeps incremental backups of only files that have changed since the previous backup. It can display backups in chronologial order so you can, for instance, easily retrieve a three-month-old version of a Pages document.
The Recovery feature of macOS even allows you to restore your system to exactly how it was on the date a backup was previously run. This
can be useful if, for instance, your computer has some form of malware and you backed up just before it took hold of your system.
This feature, however, isn’t very useful if your system is running poorly due to corrupted system files. The reason for this is quite simple – if any of your system files were damaged at the time the backup was made, your Mac will simply be replacing files with older versions of themselves which may also be damaged. You’re likely to have more success by erasing the hard drive and restoring data from the backup manually.
Target Disk Mode
The above steps assume that your system is running to the extent that you can actually run Time Machine. If this isn’t the case and you don’t have a recent backup, you still may be able to retrieve your personal files before wiping your machine and reinstalling macOS.
If you have access to two Macs with FireWire or Thunderbolt ports and the right cable, you may be able to use your Mac in Target Disk Mode. This is extremely simple to do. First connect the FireWire/Thunderbolt cable between the two Macs, then switch on your own Mac while holding down T.
A picture of a disk should appear on your screen. On the other Mac, your computer’s hard drive should then be accessible under Devices in Finder’s sidebar. Your personal data should be stored in the Users folder. It’s easiest to copy the folder named after your user account to the new computer. You can copy your own files back over to the old Mac once you’ve erased and reinstalled macOS by putting that computer into Target Disk Mode.
Last resorts
If you cannot use Target Disk Mode, you may be able to create an ‘image’ of your Mac’s hard drive using Disk Utility in macOS Recovery (go to apple.co/2nPc4bW for further advice on this). Once the copy process is complete, you’ll need to connect the drive to another Mac – you may want to do this at your local Genius Bar – to check that the files have been copied over properly.
This process doesn’t always work if files are corrupted. Your best bet in this scenario is to purchase an external hard drive and install macOS to it. You can then start up your Mac from that drive and try to access your files on the Mac’s internal hard drive.
This won’t help you recover applications but you can copy and paste over any data you created in your home folder, located in /Users. The simplest way to do this is to copy the entire home folder to the desktop.
Time Machine backups are cumulative, so it only saves files that have changed since the previous backup