Re: Strange Behavior – ZFS (and other) Storage Configuration in PVE (plain text)

[Rovshan Pashayev]

Hello Fiona,

Thank you for replies, they are very helpful.
I will update thread if anything needed more.

________________________________________
From: Fiona Ebner <f.ebner at proxmox.com>
Sent: Tuesday, July 2, 2024 13:13
To: Rovshan Pashayev <Rovshan.Pashayev at veeam.com>; pve-devel at lists.proxmox.com <pve-devel at lists.proxmox.com>; f.gruenbichler at proxmox.com <f.gruenbichler at proxmox.com>
Cc: Pavel Tide <Pavel.TIde at veeam.com>
Subject: Re: Strange Behavior – ZFS (and other) Storage Configuration in PVE (plain text)

Hi,

Am 02.07.24 um 12:37 schrieb Rovshan Pashayev:
> Hi Fiaona and Fabian,
>
> I am merging your questions and answering them in this one reply (I got reply from both of you at the same time :) )
>
>> We would like to report a strange behavior that we have encountered in Proxmox, version 8.2.2. The issue is as follows:
>> We noticed that ZFS storage configuration is missing mountpoint line randomly. And workaround is manually adding missing line.
>
> Fabina G ====
> what exactly do you mean by this? the entry in /etc/pve/storage.cfg?
> that one should only change if you call the corresponding API endpoint
> (or CLI command). please double-check the logs that no such invocation
> is happening.
>
> if you mean something else, please clearly describe how your system is
> configured and what the unexpected thing that is happening is.
>
> VEEAM's REPLY ====
> We have requested info about storage using the next command: # pvesh get storage/{storageName} --output json
> As we understand, this command just parse /etc/pve/storage.cfg and return results.
> So yes, field path and mountpoint are missed in the response of mentioned command and in the file.
> But all VM’s that have disks on this storage are working normally and can be re-started.
>

There is no 'path' property for ZFS storages in Proxmox VE. There are
'pool' and optionally 'mountpoint', see [0].

> Fiona E ====
>
> does the option get lost for already existing storages or does it affect
> newly added ones? How do you edit/add the ZFS storages, via GUI or CLI,
> please share the exact commands in the latter case. Please also note
> that the storage configuration 'mountpoint' is optional. If it is not
> set, it will be assumed to be the default mount point, i.e. the 'pool'
> configuration option prepended by '/'.
>
> VEEAM's REPLY =====
> Could you please confirm that if ‘mountpoint’ is missing in configuration it implicitly means that mountpoint is “/{pool_name}”?
>

Yes, see the code below (from [1]). If the 'mountpoint' option is not
set, the pool 'option' with a prepended '/' will be used as a fallback,
as that is the default mountpoint for a ZFS dataset:

sub path {
    my ($class, $scfg, $volname, $storeid, $snapname) = @_;

    my ($vtype, $name, $vmid) = $class->parse_volname($volname);

    my $path = '';
    my $mountpoint = $scfg->{mountpoint} // "/$scfg->{pool}";


[0]:
https://git.proxmox.com/?p=pve-storage.git;a=blob;f=src/PVE/Storage/ZFSPoolPlugin.pm;h=3669fe152b62df7ebeda572cdf56ef19be872d56;hb=13a81873ba22f37ecc0613de3f3ef994b064e3b9#l45
[1]:
https://git.proxmox.com/?p=pve-storage.git;a=blob;f=src/PVE/Storage/ZFSPoolPlugin.pm;h=3669fe152b62df7ebeda572cdf56ef19be872d56;hb=13a81873ba22f37ecc0613de3f3ef994b064e3b9#l141

Best Regards,
Fiona