Assuming Linux, oddly enough I came across this exact behavior[0] while researching resource management for an on-prem k8s cluster. Take a look at that thread f

Assuming Linux, oddly enough I came across this exact behavior[0] while researching resource management for an on-prem k8s cluster. Take a look at that thread for more info, but TL;DR, you need to actually finesse page cache constraints if you want avoid the behavior. You actually can have really fine grained control over page cache via cgroups v2[1][2] and systemd[3]. [0]: https://github.com/kubernetes/kubernetes/issues/43916 https://github.com/kubernetes/kubernetes/issues/43916 [1]: https://docs.kernel.org/admin-guide/cgroup-v2.html#memory-interface-files https://docs.kernel.org/admin-guide/cgroup-v2.html#memory-in... [2]: https://biriukov.dev/docs/page-cache/6-cgroup-v2-and-page-cache/ https://biriukov.dev/docs/page-cache/6-cgroup-v2-and-page-ca... [3]: https://www.freedesktop.org/software/systemd/man/systemd.resource-control.html https://www.freedesktop.org/software/systemd/man/systemd.res...