The Problem with Office Bandwidth
If you manage an office with 50 MacBooks, you will eventually face a massive bandwidth problem. When Apple releases a new 12GB major macOS update, all 50 MacBooks will simultaneously try to download it from Apple’s servers over the internet. That is 600GB of identical data flooding through your office router, which will instantly cripple your internet connection and bring productivity to a halt.
To solve this, Apple built a feature called Content Caching directly into macOS. When enabled on a single Mac (like a Mac mini sitting in the IT closet), that Mac acts as a local proxy. The first time a MacBook requests the 12GB update, the Mac mini downloads it from Apple and saves a copy to its own hard drive. When the other 49 MacBooks request the same update, the Mac mini serves it directly over the hyper-fast local gigabit network, using zero internet bandwidth.
While you can enable Content Caching in System Settings, system administrators need to manage it remotely, purge the cache when it gets too full, and monitor its efficiency. You can do all of this from the Terminal using the spectacularly long assetcachemanagerutil command.
Step 1: Open the Terminal
Because you are managing system-level network services, you must run these commands with root privileges.
- Press Command + Space to open Spotlight Search, type
Terminal, and press Enter. - Prefix your commands with
sudo.
Step 2: Checking the Cache Status
If you want to verify if your Mac mini is actively caching content for the network, you can run a status check.
sudo assetcachemanagerutil status
The terminal will output a detailed block of JSON data. You are looking for a few key metrics:
- Active: True or False (Is the caching service actually running?)
- CacheDetails: A breakdown of exactly what is taking up space (e.g., iOS software updates, Mac apps, iCloud data).
- CacheFree: How many bytes of hard drive space are still available for caching new data.
Step 3: Flushing the Cache
If your caching Mac mini only has a 256GB hard drive, it can fill up very quickly. If you need to instantly reclaim that space for other IT projects, you do not need to hunt through hidden system folders to delete the files manually. You can tell the utility to flush everything instantly.
sudo assetcachemanagerutil flushCache
The terminal will instantly delete all downloaded Apple updates and iCloud data stored in the cache, returning your hard drive to its normal state.
Step 4: Reloading the Settings
If you use a Mobile Device Management (MDM) profile or a Terminal command to change the amount of hard drive space the cache is allowed to use, the caching engine does not always recognize the new limit immediately.
Instead of completely rebooting the server to force the changes to take effect, you can simply tell the daemon to reload its configuration files on the fly.
sudo assetcachemanagerutil reloadSettings
This ensures your new bandwidth or storage limits are applied instantly without interrupting any ongoing downloads on the local network.