[PVE-User] Why are images and rootdir not supported on CephFS?
f.gruenbichler at proxmox.com
Mon Feb 17 07:23:25 CET 2020
On February 16, 2020 5:26 pm, Frank Thommen wrote:
> Thank you for the link.
> Even though Fabian Gruenbichler writes in the bugreport
> (https://bugzilla.proxmox.com/show_bug.cgi?id=2490#c2) that Ceph RBD
> offers all features of CephFS, this doesn't seem to be true(?), as
> CephFS supports "vztmpl iso backup snippets" and Ceph RBD "images
> rootdir" (https://pve.proxmox.com/pve-docs/chapter-pvesm.html), so these
> two storage types are complementary and RBD cannot replace CephFS.
that comment was about using CephFS for guest image/volume storage. for
that use case, RBD has all the same features (even more), but with
better performance. obviously I didn't mean that RBD is a file system ;)
> What would be a good practice (CephFS and RBD are already set up):
> Create an RBD storage on the same (PVE based) Ceph storage that already
> has CephFS on top of it and use one for templates and backups and the
> other for images and rootdir?
> Won't it create problems when using the same Ceph pool with CephFS /and/
> RBD (this is probably rather a Ceph question, though)
you don't use the same Ceph pool, just the same OSDs (pools are logical
in Ceph, unlike with ZFS), so this is not a problem.
> Additionally this might create problems with our inhouse tape backup, as
> I don't think it supports backing up object storage...
the usual backup options are available - use vzdump, and then backup the
VMA files. or use some backup solution inside the guest. or both ;)
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