What does buffered, cached, free, slab and used mean when monitoring memory use on GKE?

I am running some compute nodes on GKE and when I look on their memory usage in metrics explorer I see:

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It is clear to me what used and free mean. But how about the other states?

The official documentation is quite terse on the subject.


Solution 1:

That is standard terminology of Linux Kernel management:

buffered - Block device (e.g. harddisk) cache

cached - Parked file data (file content) cache

slab - Memory used by the kernel to cache data structures for its own use (caches like inode, dentry, etc)