[SOLVED] backing up VMs to ZFS [again]

[Daniel Drucker]

This has been asked and answered multiple times, but always with lots of confusion and conversation, and I can't seem to get any of the advice in previous threads to work.

I have two SSDs in RAID1, and two HDDs also in RAID1. The SSDs are where Proxmox (6.2) is installed.

root@proxmox03:/# zpool list
NAME           SIZE  ALLOC   FREE  CKPOINT  EXPANDSZ   FRAG    CAP  DEDUP    HEALTH  ALTROOT
big-and-slow  1.81T   480K  1.81T        -         -     0%     0%  1.00x    ONLINE  -
rpool          888G  16.0G   872G        -         -     0%     1%  1.00x    ONLINE  -
root@proxmox03:/# zfs list
NAME               USED  AVAIL     REFER  MOUNTPOINT
big-and-slow       396K  1.76T       96K  /big-and-slow
rpool             16.0G   844G      104K  /rpool
rpool/ROOT        16.0G   844G       96K  /rpool/ROOT
rpool/ROOT/pve-1  16.0G   844G     16.0G  /
rpool/data          96K   844G       96K  /rpool/data

I would like to be able to do VM backups to "big-and-slow". I've tried following instructions at https://forum.proxmox.com/threads/zfs-type-does-not-allow-backup-storage.52266/ and https://forum.proxmox.com/threads/prevent-auto-folder-creation-before-manual-mount.31133/ but have gotten nowhere.

Can anyone help let me know what I need to do?

 

[LnxBil]

If you only want to have backups on your big-and-slow, you can just add a directory storage:



Yet I strongly recommend to create another dataset for that:

zfs create big-and-slow/backups

and use /big-and-slow/backups as the directory in the screenshot.

 

[Stoiko Ivanov]

The hints in the other threads should work - please post your '/etc/pve/storage.cfg'

 

[Daniel Drucker]

root@proxmox01:~# cat /etc/pve/storage.cfg
dir: local
	path /var/lib/vz
	content iso,vztmpl,backup

dir: proxmoxstorage
	path /proxmoxstorage
	content vztmpl,rootdir,iso,snippets,images,backup
	maxfiles 1
	shared 0

zfspool: big-and-slow
	pool big-and-slow
	content images,rootdir
	mountpoint /big-and-slow
	nodes proxmox03

nfs: durga-proxmox-backups
	export /data/proxmox-backups
	path /mnt/pve/durga-proxmox-backups
	server durga.mclean.harvard.edu
	content iso,backup
	maxfiles 3

dir: backup
	path /big-and-slow/backups
	content backup,images
	maxfiles 4
	nodes proxmox03
	shared 0
	mkdir 0

But it is still seemingly having issues with /big-and-slow/backups being created and used before the ZFS mount happens.

 

[Stoiko Ivanov]

try adding the is_mountpoint option (set to 1)( for dir: backup)

I hope this helps!

 

[Daniel Drucker]

Huh! That seemed to do it. I must have set is_mountpoint in the wrong place before. Thanks.

 

[Stoiko Ivanov]

Glad that worked!

 

[bertd2]

I found this thread using Google, and found that it solved my issue as well! The is_mountpoint 1 trick saved my day (after the fallout from not having it ate up 4% of my SSD lifetime, but I digress : -)

This is not the first tweak I had to make to a config file for functionality that is not exposed in the GUI. Every time, including this one, Google pointed me the way, but I'm left with the feeling that I'm missing the obvious: a link to the official documentation. If I Google for "proxmox" "is_mountpoint", I find numerous posts on the forum that describe the problem I have, and I now know that the pvesm manpage documents the --is_mountpoint option which translates in the "is_mountpoint 1" option in storage.cfg. But I feel I'm overlooking the obvious: there must be a clue hidden in the GUI that tells me that the pvesm manpage is behind the "Storage -> Directory" menu item. Because I'm looking in that menu and its help screen for info about what's happening.

Think of it as a "for further reading" link. And if it doesn't exist yet, I'd like to advocate for adding it. Is there a manpage or web page that maps GUI items like "Storage -> Directory" to pvesm?

 

[LnxBil]

But it is still seemingly having issues with /big-and-slow/backups being created

You did not create the directory or dataset before adding it as a mountpoint?