about automatic disk storage management

I saw this sentence at unity accelerator official docs.

it features automatic disk storage management. This means that it will periodically clean up unneeded assets and/or source. With the original Cache Server, teams often had to use additional tooling to manage disk space.

i want to know how accelerator judge assets or sources that are unneeded?
and how am i set this management period.

Hey kjhtree3,

The eviction is LRU-based (it deletes least recently used files first) until it reaches the thresholds set in the configuration.

By default, Accelerator's eviction policy will begin evicting items from the cache when the volume hosting the configured storage directory reaches 5% or 1 GiB of free space remaining (whichever is reached first). Evictions will continue until the volume's usage has at least 5 GiB or 10% free space available. You can control these values by changing the config parameters listed below.

These are the related unity-accelerator.cfg options you can change, either in the dashboard (http://localhost:8080/dashboard/#/config-page - change the address if you are using another machine) or by editing the unity-accelerator.cfg by hand or through using the command line tool unity-accelerator config set :

  • CacheMaxUsedBytes - The maximum number of bytes the cache should use. The cache will begin evicting items if the space used by the cache exceeds this threshold.
  • CacheMaxUsedPercent - The maximum percentage of disk space the cache should use. The cache will being evicting items if the percentage of space used by the cache exceeds this threshold.

You can also limit by overall disk free space (set to -1 to disable an option):

  • CacheMinFreeBytes - The minimum number of bytes to try to keep free. The cache will begin evicting items if the free space drops below this threshold.
  • CacheMinFreePercent - The minimum percentage of free space to try to uphold. The cache will begin evicting items if the percentage of free space drops below this threshold.

The following options are how the Accelerator will behave once the allowed space is reached (-1 to disable an option):

  • CacheEvictUntilFreeBytes - Once an eviction pass begins, this value will indicate when to stop evicting -- when the free bytes meets or exceeds this value.
  • CacheEvictUntilFreePercent - Once an eviction pass begins, this value will indicate when to stop evicting -- when the percent of free space meets or exceeds this value.
  • CacheEvictUntilUsedBytes - Once an eviction pass begins, this value will indicate when to stop evicting -- when the used bytes are less than or equal to this value.
  • CacheEvictUntilUsedPercent - Once an eviction pass begins, this value will indicate when to stop evicting -- when the percentage of used space is less than or equal to this value.

Reference:
https://docs.unity3d.com/2022.1/Documentation/Manual/UnityAccelerator.html#admin