[PVE-User] Backup to Ceph / NFSv4

[Uwe Sauter]

Followup to NFSv4:

It seems that TCP-based NFSv4 is currently not possible due to several issues:

* PVE uses "pvesm nfsscan <host>" to get a list of exports from the NFS server. This tool internally uses showmount which uses UDP
as protocol and has no fallback to TCP. Thus, the exports lookup fails and PVE does not mount.

# pvesm nfsscan <host>
clnt_create: RPC: Port mapper failure - Unable to receive: errno 113 (No route to host)


* WebUI does not allow to configure mount options, e.g. necessary to select NFS protocol.

* Manually trying to mount NFSv4 failes with:

# mount -t nfs -o vers=4,rw,sync <host>:$SHARE /mnt
mount.nfs: mounting aurel:/proxmox-infra failed, reason given by server: No such file or directory

Tested with $SHARE being several values, e.g. /exports/proxmox-infra, /backup/proxmox-infra, /proxmox-infra

On the server, /etc/exports looks like:

/exports               192.168.253.192/26(rw,fsid=0,no_subtree_check,sync,crossmnt)
/exports/proxmox-infra 192.168.253.192/26(rw,sync)

and /exports/proxmox-infra is a symlink to /backup/proxmox-infra.


On the other hand, manually mounting NFSv3 works:

# mount -t nfs -o vers=3,rw,sync <host>:/backup/proxmox-infra /mnt

but again, due to showmount not using TCP PVE will not mount it automatically.



Regards,

	Uwe



Am 18.05.2017 um 11:40 schrieb Uwe Sauter:
> Hi,
> 
> as my Proxmox hosts don't have enough local storage I wanted to do backups into the "network". One option that came into mind was
> using the existing Ceph installation to do backups. What's currently missing for that (as far as I can tell) is Proxmox support
> for a Ceph-backed filesystem (CephFS) including a Ceph metadata server.
> 
> CephFS would also allow to store ISO images so that there is no need to have local copies (which are required on every host where
> a VM can be migrated to (if the VM's DVD drive is currently connected to the ISO)).
> 
> Are there plans to support CephFS in the future?
> 
> 
> Lacking CephFS support I wanted to use a remote NFSv4 server for backups (as TCP-based NFSv4 is easier to configure in firewalls).
> Is the information on [1] still correct? With PVE 4.4 I don't have the option to select a NFS version (or any other NFS mount
> option at all) but the wiki page suggests otherwise.
> 
> Will TCP-only NFSv4 work with PVE? My iptables config on the NFS server side is:
> 
> […]
> -A INPUT -s 192.168.253.192/26 -p tcp -m state --state NEW -m tcp --dport 111 -m comment --comment "NFS: Portmapper" -j ACCEPT
> -A INPUT -s 192.168.253.192/26 -p tcp -m state --state NEW -m tcp --dport 662 -m comment --comment "NFS: Statd" -j ACCEPT
> -A INPUT -s 192.168.253.192/26 -p tcp -m state --state NEW -m tcp --dport 875 -m comment --comment "NFS: Quota" -j ACCEPT
> -A INPUT -s 192.168.253.192/26 -p tcp -m state --state NEW -m tcp --dport 892 -m comment --comment "NFS: Mountd" -j ACCEPT
> -A INPUT -s 192.168.253.192/26 -p tcp -m state --state NEW -m tcp --dport 2049 -m comment --comment "NFS: NFSv4" -j ACCEPT
> -A INPUT -s 192.168.253.192/26 -p tcp -m state --state NEW -m tcp --dport 32803 -m comment --comment "NFS: Lockd" -j ACCEPT
> […]
> 
> 
> 
> Regards,
> 
> 	Uwe
> 
> 
> 
> [1] https://pve.proxmox.com/wiki/Storage:_NFS
>