Because of the complexity, we won’t be addressing core storage tricks, or resizing or partitioning Fusion Drives in this article.įusion Drives and Boot Camp are another special case. To add another wrinkle, partitions that are part of a Fusion Drive can’t be resized using the Disk Utility GUI, even though it’s possible (though very complicated) to resize using the Terminal core storage commands. Apple allows a Fusion Drive to have up to two partitions however, the SSD is never included in the second partition, which is made up only of the conventional hard drive. They’re made from two separate disks: a fast SSD and a slower, but much larger, conventional disk drive. Currently, only disks formatted with the GUID Partition Map support resizing.įusion Drives are a special case. Resizing is limited to specific disk formats. In addition, there are times when, because of the type of changes you wish to make, you’ll be forced to delete one or more partitions to accomplish your goals having a backup is key to a guaranteed successful completion. Although the basic idea is to resize a volume without losing data, it’s always better to play it safe. Be sure to pay attention to these rules.Īlso, it’s a good idea to have a current backup. For the most part, the resizing capabilities in Disk Utility need some careful attention to details to ensure the results you want will occur.
We’re going to look at how to resize a partition without losing data with the new (OS X El Capitan and later) version of Disk Utility.ĭisk Utility can be used to resize existing partitions you may have on a disk, but there are some rules that govern whether you’ll be able to make the changes you envision.
(Disk Utility from older versions of the Mac OS was arguably easier to use for resizing partitions.)
Resizing was pretty straightforward with OS X Leopard through OS X Yosemite, but starting with OS X El Capitan, Disk Utility underwent a user interface makeover that altered how partitions were resized. Thankfully, you can now resize a partition without losing data, provided you follow a few basic rules. That’s because changing the partitions, by adding, removing, or resizing, resulted in the loss of all data on the volume. Before OS X Leopard, you needed to fully back up all the data on a drive if you intended to alter the drive’s partition map in any way. With the advent of OS X Leopard, Disk Utility picked up a much-prized feature: the ability to non-destructively resize existing volumes and partitions. It has been the go-to tool for formatting a Mac’s drives, erasing data, securely wiping information, and creating multiple partitions. Disk Utility, the all-purpose tool for working with storage devices connected to the Mac, has long had the ability to create partitions and manage the resulting volumes.