Volume level caching

Adverbial_Fish

New Member
Apr 3, 2026
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hello proxmox community!

I am in need of some advice pertaining to pve, storage configurations and what is possible natively to proxmox without editing the base installation.
I have already looked on https://pve.proxmox.com/wiki/Storage#_storage_configuration and was unable to find, or perhaps unable to understand the answer to my question.
I have a planned build I am working on and would like to set up volume level cacheing so that "hot" data is stored on SSD's and "cold" data on mechanical.
from my research I do NOT want L2ARC with zfs, as that is not true read/write caching and typically writes are cached in ram before the transaction log is flushed to disk. (I am aware of the SLOG, but this still is not suitable for my use case.)

from what I can tell I could use dm-cache from the terminal to achieve what I want (or close to it) on an lvm/lvm-thin but I would prefer not making any changes to the base PVE install if I can avoid it. I am not sure and have not been able to find any evidence one way or the other that this is possible in pve 9.

in case the info is needed, the planned install would be a 24+2 bay 2U chassis. pve installed on the +2 bays and bays 20-23 would be set aside for caching ssd's. data would reside on one or more volumes in bays 0-19.

thank you for your time in reading this and any assistance you may be able to offer. (even if its just telling me to read the proper documentation as I haven't even been able to find that...)
 
Hi,
It sounds like you are looking for a Tiered Storage or Hybrid Volume solution where the movement of data between SSD and HDD is handled transparently by the storage layer. To address your specific requirement: Proxmox Virtual Environment (PVE) does not currently support native, GUI-driven automated tiering or read/write volume caching (like dm-cache or bcache) without dropping to the CLI. Proxmox is essentially Debian with a custom kernel, a specialized API, and a Web GUI. The GUI is designed to manage "Standard" storage types: ZFS, LVM, LVM-Thin, NFS, SMB/CIFS, and Ceph.

While the underlying Debian OS supports dm-cache, bcache, and OpenCAS, Proxmox does not have a management layer for these in the Web interface. If you configure them via the CLI, Proxmox will see the resulting logical volume as a standard "LVM" or "Directory," but you will have "edited the base installation" via the terminal to get there.