Hi there. I am looking to potentially evaluate migrating my storage systems from ZFS to Ceph and my question is, is there something like ZFS' adaptive replacement cache (ARC) on Ceph? I am asking because I am looking to potentially deploy four nodes with six HGST 6 TB SATA HDDs in each node, where each HDD will become a Ceph OSD. My concern is that without something like ZFS' ARC, if it has to read the data from disk every single time, that it can be really slow, especially for repeat reads. I found this old thread talking a little bit about this: https://ceph-users.ceph.narkive.com/vPnNl3zj/cephfs-and-caching#, but as noted, it is a rather old thread by now, so I am wondering what is the state of caching with Ceph? I understand that cache tiering has been deprecated due to the lack of a maintainer. It is also my understanding (via the above mentioned older thread) that ZFS ARC works a little differently than the "general" linux cache. Your help in educating me how this works in 2026, is greatly appreciated. Thank you. Sincerely ~alpha