Content Caching: How It Works

Unfortunately, Apple is pretty much discontinuing macOS Server. It is still available, but with greatly reduced features. Once of the missing features from Server is something called Content Caching. However, if you are running macOS High Sierra, you can activate Content Caching on your Mac. Content Caching could be a very useful feature depending on your Mac workflow. Lets take a look at what Content Caching is, then you may wish to set it up on your system.

Content Caching

So, what is Content Caching? This definition is a s good as any:

Once Content Caching is enabled on a Mac, it keeps copies of all of the software updates, App Store downloads and updates, and iCloud data, including backups to iCloud that are initiated by any client connected to your local network.

The next time a client on your network needs to download the same data, such as a macOS update, the data is retrieved from the content cache instead of being downloaded from the Internet. All subsequent client devices that need the data get it from the local network at what will normally be a much faster connection than is possible from the Internet.

I think you can see how this would be beneficial in a work Environment where several Macs are deployed. However, it may also be useful in a home network environment, especially if you have several active Macs and iOS devices.

Content Caching Setup

I think this goes without saying, but Content Caching is going to take up quite a bit of hard drive space. The articles I have read suggest setting it up on your Main hard drive if it happens to be quite large. Most of the time setting up Content Caching on an external drive is what is recommended.

To setup Content Caching go into the Sharing Preference Pane:

Content Caching Start

I have already activated Content Caching, but what is recommended is to click on “Content Caching” in the sidebar to select it, but do not check the box to activate it. Then, select what you want to Cache in the drop down menu (in my case All Content). Then click on Options to get to this screen:

Options Screen

Here you have to select your Cache Location by clicking the Edit button. In my case I selected an External USB 3.0 Hard Drive running a 525 GB Crucial SSD:

Cache Location

Once you have selected the Cache Location, you have to determine how much space to assign to the Cache:

Cache Space

Since my Cache drive is not too large, I selected “Unlimited”, YMMV. Once you are finished in the Options area, click OK. Then, turn on Content Caching by clicking in the checkbox. You will see a window stating “Content Caching is moving data . . .”

Moving Data

When that is finished you should get this message:

Restart Devices

After activating Content Caching, I Restarted my iMac. I also Restarted my iPhone 8 and iPad Pro.

When I checked my Content Cache drive it had about 160 MB of Data on it. I will have to see how this works over time, but for now it seems like a pretty cool feature, especially if you have multiple Macs and other devices in your household or small business.


If you have the drive space, either internally or externally, you might give this a try. I think it will save you some time in the long run to not have to wait for different kinds of things to download.