How to set the cache size in Linux?

6 months ago

2 minutes

In Linux, cache size is automatically managed by the operating system, typically adjusting dynamically based on the system’s memory size and usage. Users generally don’t need to manually set cache size, as the operating system will allocate memory to the cache as needed.

However, if you want to manually adjust the cache size, you can do so by modifying kernel parameters. You can set the cache size by changing the values in the files /sys/block/{device}/queue/writeback_cache_min and /sys/block/{device}/queue/writeback_cache_max. Here, {device} refers to the name of the device you want to adjust, such as sda.

Additionally, you can adjust the cache usage percentage by modifying /sys/block/{device}/bcache/writeback_percent. This parameter represents the percentage of total memory used by the cache and can be adjusted as needed.

Please note that manually adjusting cache size may affect system performance and stability. It is recommended to proceed with caution and test the effects.