[PVE-User] Ceph and cold bootstrap...

Marco Gaiarin gaio at sv.lnf.it
Mon Sep 19 11:48:37 CEST 2016

Mandi! Adam Thompson
  In chel di` si favelave...

> Soft-mounting NFS introduces the *possibility* of accidental (and silent) data loss in corner cases, however.  There's a lot of strident "soft-mounting is dangerous!" rhetoric on the net, it is a reasonable option in many cases as long as you understand the corner cases where data loss can occur silently and either mitigate them or deliberately accept the risk in exchange for the benefits of soft-mounting.
> Personally, I use "soft,intr" in almost all cases, but that's because I'm willing to accept the possibility of silent data loss if my NFS server goes down moments before my PVE servers.  (Note that silent data loss in a QCOW2 file could also mean the QCOW2 file becomes corrupt and unusable... the same applies to VMDK, but should theoretically not be a problem with RAW.) 

There's some guidelines about NFS for proxmox? I'm using an NFS-mounted
dir for backups, and the ''nfs server'' are on one of the three node
(3jane), where i've in /etc/exports:

	/srv/pve	tessier(rw,async,no_root_squash,no_subtree_check) ashpool(rw,async,no_root_squash,no_subtree_check) 3jane(rw,async,no_root_squash,no_subtree_check)

Mount options are:

	root at 3jane:~# grep 3jane /etc/mtab 
	3jane:/srv/pve /mnt/pve/Backup nfs rw,relatime,vers=3,rsize=1048576,wsize=1048576,namlen=255,hard,proto=tcp,timeo=600,retrans=2,sec=sys,mountaddr=,mountvers=3,mountport=37667,mountproto=udp,local_lock=none,addr= 0 0

And, supposing for the 'bootstrap' problem (the node are trying to
unmount a FS that was mounted by the server itself, and the NFS server
is just stooped ;), rebooting node 3jane is a bit problematic. ;-)

I've set:

	options vers=3,soft,intr

on /etc/pve/storage.cfg, but there's some optimal/preferred/useful nfs
export options also?


PS: backup is only a scratch space, all data then get transferred to

dott. Marco Gaiarin				        GNUPG Key ID: 240A3D66
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