- Reference 16.1 Understanding the Caching Service
- Reference 16.2 Configuring and Maintaining the Caching Service
- Reference 16.3 Comparing Software Update and Caching Services
- Reference 16.4 Troubleshooting the Caching Service
From the book
From the book
From the book
Reference 16.2 Configuring and Maintaining the Caching Service
It’s really simple to configure the Caching service. You could click the On/Off switch to turn the service on and be done configuring.
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The Server app allows a few configuration features. You can:
- Click the link next to Status to learn more about configuring this service.
- Click Edit to select a volume for caching.
- Use the slider to set the cache size.
- Deselect the checkbox “Only cache content for local networks” to serve only clients on subnets that your server is not directly connected to (for complex networks).
- Click Reset to erase the existing cached content.
The volume you select to use for the Caching service must have at least 50 GB free (even if you set the Cache Size slider to 25 GB). If you select a volume that doesn’t have enough space, the Server app alerts you, and the Choose button becomes unavailable. Simply select a different volume.
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By default, the Caching service uses the startup volume for the cached content. Even though the slider is labeled “Unlimited,” the Caching service is smart enough to not fill up the entire volume; when only 25 GB is left on the volume you’re using for the Caching service, your server deletes the least recently used cached content (not necessarily the oldest content) to make space for new content. If your users download a large variety of different content, consider using a volume large enough to cache as much content as you can, otherwise the Caching service may constantly delete items that it will end up downloading again, after deleting yet more items in order to make room for the newly requested items.
If you change the volume used for the Caching service, the existing cached content will be copied to the newly selected volume.
MORE INFO ▶ See the “Configure advanced cache settings” section of the OS X Server: Advanced Administration guide (https://help.apple.com/advancedserveradmin/mac/3.0/) for more advanced options, such as limiting the network interfaces on which the service listens and limiting the number of concurrent client connections.
Because of the nature of the Caching service, it will not start unless your server has a wired Ethernet connection.
If your organization has a number of subnets that are all behind the same network device that performs NAT, and they all have the same public IPv4 address, but the internal subnets have slow links between them, you may want to select the checkbox “Only cache content for local networks” so that each subnet has its own local copy of items. This way, clients on each subnet can download cached content quickly from a local Caching server, as opposed to using up the slow link between subnets. Caching servers will download content from their peers, if available, rather than from the Internet.
The Usage section shows you at a glance the kind of content your Caching server has downloaded.
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The Stats pane of the Server app has one graph dedicated to the Caching service. Start by selecting the Stats pane in the Server app sidebar. Use the pop-up menus to choose Bytes Served as the type of activity, then choose a time period. The graph shows how much data the Caching service has downloaded from the Internet and from other peer servers, and how much it has served to clients from its cache.
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