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Upgrading Your System Drive
You can upgrade your system drive without having to reinstall anything.
It's called cloning and you can do it quickly and easily; it’s not technical. After cloning, replace the old drive with the new one and you’ll be up and running exactly as before.
The Voyager Q Drive Dock is perfect for cloning an internal (bare) drive for notebook and desktop Macs, because you can clone to the new (bare) drive, then swap the old drive for the new one.
The same result can be achieved by first cloning to a temporary drive of any kind, installing the new drive, then booting off the clone and then cloning it to the newly installed drive.
If the new drive capacity is smaller than the old one (perhaps you are switching from a hard drive to an SSD), then your data must of course fit onto the new drive. Always delete unused files, caches, etc, then if there is still too much stuff, migrate some of it to a separate data drive.
Simply clone your old system drive to the new one as shown below*: