Libro sobre Proxmox maestria
Chapter 7
We can store any files, including ISO, templates, backups, and OpenVZ containers, in this storage. Since both RBD and Ceph FS are on the same hardware, we do not recommend that you store backups primarily on Ceph FS. Backup should always be done on separate hardware. The best course of action would be setting up a separate Ceph cluster with Ceph FS only and storing Proxmox backups there. However, for a light load, such as storing ISOs and templates, Ceph FS works great. This eliminates the need to have separate file storage such as FreeNAS or any other type of storage to store ISO images, templates, or OpenVZ containers.
Ceph FS has not yet reached industry quality according to the Ceph developers. Minor occasional glitches are to be expected. But from my personal experience, even after using Ceph FS for 11 months straight on a regular basis, I have not came across any glitches or disappointment.
We now have a working Ceph cluster with RBD and Ceph FS connected to our Proxmox cluster. In the next section, we are going to look at Ceph's CRUSH map and how we can manipulate it to customize a Ceph cluster.
A CRUSH map is the heart of Ceph's storage system. The algorithm of CRUSH dictates how data is stored and retrieved through the Ceph cluster. The topic of CRUSH alone is worthy of an entire book, but here, it is sufficient to understand that learning to manipulate CRUSH provides administrator an upper hand in storage management. It is only by manipulating CRUSH that we can set up a multitiered Ceph cluster to store virtual machines based on performance requirements.
Using CRUSH, we can move OSD from one node to another or even move an entire node to a different location without causing major disruption in the storage service. A CRUSH map is not readily available in the Ceph admin directory. We have to use CRUSH commands to extract, edit, and inject a CRUSH map back into a Ceph cluster. Basically, it is a five-step process:
5. Inject the map back into the cluster.
Let's look into a CRUSH map by first extracting it from the Ceph cluster. The CRUSH map will always need to be extracted first and decompiled to make it humanly readable, and then recompiled before injecting it into Ceph cluster.