Log entries are purged from storage according to elaborate rules explained here, for different types of log entry. How to extend time coverage in those logs, and how to get free statistics about them.
logarchive
An introduction to the Unified log used on Macs and Apple’s devices. Its goals, how logs are stored and maintained, their content, privacy protection, and tools available to access them.
If you only have access to the log files of a Mac or device and can’t create a logarchive of them, this new build offers a solution, plus detailed info about a logarchive to help you browse its contents.
LogUI can now read and browse saved logarchive packages, including those from other Macs, and iOS and iPadOS devices.
macOS logs may only last a few days, or even hours, into the past. Here’s a quick and simple way of browsing the log from weeks, months or even years ago.
There are 3 different ways to access the log, and its entries will be different depending on which way you use. This explains the differences and methods.
Apple: “The logs are typically very overwhelming.” So what can the user do to get information about iCloud Drive problems?
Safeguard your Mac, take screenshots, capture the logs in a logarchive or with sysdiagnose, make a written record, then repair and recovery.
How can you browse a logarchive sent from an iPhone, iPad, or someone else’s Mac? With Ulbow it’s really simple – and it can create logarchives too.
Console is the epitome of Apple’s problem with tools and support for its users, and is exactly what it needs to fix.
The Eclectic Light Company 