You can upgrade to OS X El Capitan from OS X Snow Leopard or later on any of the following Mac models. Your Mac also needs at least 2GB of memory and 8.8GB of available storage space.
MacBook introduced in 2009 or later, plus MacBook (13-inch, Aluminum, Late 2008) MacBook Air introduced in late 2008 or later MacBook Pro introduced in mid 2007 or later Mac mini introduced in early 2009 or later iMac introduced in mid 2007 or later Mac Pro introduced in early 2008 or later Xserve models introduced in early 2009
To find your Mac model, memory, storage space, and macOS version, choose About This Mac from the Apple menu . If your Mac isn't compatible with OS X El Capitan, the installer will let you know.
Make a backup
A drive can be used on any type of computer - PC or Mac. But in order for the computer and drive to talk to one another, the drive has to be formatted. This article explains about file systems and provides instruction to format a drive on Windows and Mac.
Before installing any upgrade, it’s a good idea to back up your Mac. Time Machine makes it simple, and other backup methods are also available. Learn how to back up your Mac.
Get connected
It takes time to download and install OS X, so make sure that you have a reliable Internet connection. If you're using a Mac notebook computer, plug it into AC power.
Download OS X El Capitan
For the strongest security and latest features, find out whether you can upgrade to macOS Catalina, the latest version of macOS.
If you still need OS X El Capitan, use this link: Download OS X El Capitan. A file named InstallMacOSX.dmg will download to your Mac.
Install the macOS installer
Double-click the downloaded file to open a window showing its contents. Then double-click the file within, named InstallMacOSX.pkg.
Follow the onscreen instructions, which will guide you through the steps necessary to install.
Begin installation
After installation of the installer is complete, open the Applications folder on your Mac, then double-click the file named Install OS X El Capitan.
Click Continue and follow the onscreen instructions. You might find it easiest to begin installation in the evening so that it can complete overnight, if needed.
Allow installation to complete
Please allow installation to complete without putting your Mac to sleep or closing its lid. Your Mac might restart, show a progress bar, or show a blank screen several times as it installs both OS X and related updates to your Mac firmware.
Learn more
OS X El Capitan won't install on top of a later version of macOS, but you can erase your disk first or install on another disk.
You can use macOS Recovery to reinstall macOS.
Summary
Disk Utility got a facelift with the launch of OS X El Capitan. But this makeover didn’t go well for a handful of Mac users. Some of them find difficult to perform regular disk management activities on Apple hard disk drives including partitioning the disk, creating, resizing and deleting a partition.
Good News Arriving Soon
Very soon we will need to partition our Mac hard drive in order to make room for macOS Sierra installation which Apple announced this WWDC 2016 in San Francisco.
Tip
But before the time arrives to partition the Mac hard drive for macOS Sierra installation, it is equally necessary to backup the data on Mac startup disk drive to avoid losing any files during the upgrade or installation processes.
OS X El Capitan Partitioning
With the help of screenshots, I will be explaining some basic set of activities that are to be done while partition the OS X El Capitan drive. Alternatively, the same procedure will be explained with the help of a disk manager utility known as Stellar Partition Manager.
Background
I am using an old 40 GB external hard drive to create, resize and delete partition with Disk Utility and Stellar Partition Manager software.
** Resolving Partition Option Greyed Out issue
Select the external disk from the left side of Disk Utility
Unfortunately, the Disk Utility partition option is greyed out (see below screenshot)
Solution: Select the ‘Generic USB Disk Media’ and the partition option will become active.
Partition Button is Now Active
Click the Partition button to start partitioning the external drive
Task 1) To create 3 Partitions of below sizes (using Disk Utility)
Partition A = 20 GB
Partition B = ~10 GB
Partition C = ~10 GB
Step 1) Enter partition name and format i.e. ‘Partition A’ and ‘OS X Extended Journaled’
Step 2) Enter partition size i.e. 20 GB. Press Return and slider will automatically take 20 GB. Else drag the slider to occupy 20 GB of spaces for partition A.
Now select the 19.7 GB of the remaining hard drive spaces and click (+) plus sign. Name the 2 partitions as B and C.
Partition B and C Size
As shown above, the external hard drive is divided into 3 partitions of sizes 20GB, and two almost 10 Gb of partitions. Click Apply to save the changes.
Outcome Looks Good
Task 2) To resize the 3 partitions as below requirement (using Disk Utility)
Resize ‘Partition A’ to 15 GB
Resize Partition B to ~12 GB
Resize ‘Partition C’ to ~13 GB
Now, here the problems arrives
Unable to resize Mac partition
Entered 15 GB for Partition A and pressed Return. The ‘Partition A’ shrinks to 15 GB but created a new partition of 5 Gb, which is unused.
Now as per our second task, we need to create around 12 Gb for Partition B. Let’s see if Disk Utility allows us to do it perfectly.
Unfortunately, neither the mouse slider nor the Size box is accepting the Partition B to expand to ~ 12 Gb in size. The same issue is bothering ‘Partition C’ which is not expanding to ~13 Gb of size either through the partition slider or with the help of the size box.
No Productivity
Since the partitioning as mentioned in Task 2 cannot be done with the help of Disk Utility on OS X El Capitan we will choose to achieve this task with the help of Stellar Partition Manager utility.
Stellar Partition Manager
Task 3) To resize the 3 partitions as below requirement (using Mac disk manager software)
Format Seagate Hard Drive For Mac El Capitan Update
Resize ‘Partition A’ to 15 GB
Resize Partition B to ~12 GB
Resize ‘Partition C’ to ~13 GB
Witness the difference b/w Disk Utility and Stellar Partition Manager
Fortunately, Stellar Partition Manager utility collects all the available free spaces on the Mac hard drive or an external hard drive and uses it efficiently for resizing the Mac partitions.
Stellar Partition Manager
Now let’s achieve our tasks
Format Seagate Hard Drive For Mac El Capitan Download
** Resize ‘Partition A’ to 15 GB by using the mouse to drag the edge and shrink the partition size from 20 GB to 15 GB
** Time to resize ‘Partition B’ to ~ 12 GB
12 GB Resize Easily Done
** Time to resize / expand ‘Partition C’ to claim all available free spaces. In the above screenshot, you can see that Partition C is of size 8.3 Gb and only 1.74 GB of free spaces are available. Hence it will take all the free spaces but this external hard drive is only 40 in size so the final size of the Partition C will be 9.42 GB.
Format Seagate Hard Drive For Mac El Capitan Upgrade
Mac Partition Resizing Done Successfully With Stellar Partition Manager
Format Seagate Hard Drive For Mac And Windows
Click the Start button mounted on the top menu bar to apply the changes. Hence, we have achieved the partition-resizing task up to 90% with the help of Stellar Partition Manager utility. Concluding this article with: How to create bootable USB on Mac with Stellar Partition Manager application.