Proxmox is a cluster-based hypervisor. It is meant to be used with several server nodes. By using multiple nodes in a cluster, we provide redundancy or high availability to the platform while increasing uptime. A production virtual environment may have several dozens to several hundreds of nodes in a cluster. As an administrator, it may not be a realistic scenario to change configuration files in the cluster one node at a time. Depending on the number of nodes in a cluster, it may take several hours just to change one small argument in a configuration file of all the nodes. To save precious time, Proxmox implemented the clustered filesystem to keep all the configuration files or any other common files shared by all the nodes in the cluster, in a synchronous state. Its official name is Proxmox Cluster file system (pmxcfs). The pmxcfs is a database-driven filesystem used to store configuration files. Any changes made to any files or copied/deleted in this filesystem get replicated in real time to all the nodes using corosync. The Corosync Cluster Engine is a group communication system used to implement high availability within an application. You can learn more about corosync by visiting the link: http://corosync.github.io/corosync/.

Any file added to this filesystem almost instantly gets replicated to all the nodes in the cluster, thus saving an enormous amount of time for a system administrator.

The pmxcfs filesystem is mounted at the following path:

# /etc/pve 

All cluster-related files are stored in this folder path.