Re: [pve-devel] [RFC guest-common 09/13] vzdump: schema: add fleecing property string

[Fiona Ebner <f.ebner@proxmox.com>]

Am 25.01.24 um 15:41 schrieb Fiona Ebner:
> +    storage => get_standard_option('pve-storage-id', {
> +	description => "Use this storage to storage fleecing images. Default is to use the same "
> +	    ."storage as the VM disk itself.",
> +	optional => 1,
> +    }),
> +});
> +

LVM and non-sparse ZFS need enough space for a copy for the full disk
up-front, so are not suitable as fleecing storages in many cases. ISCSI
doesn't allow disk allocation. Should such storages be outright
forbidden as fleecing storages or should it just be documented? Should
the setting rather be VM-specific than backup job-specific? These issues
mostly defeat the purpose of the default here.

IIRC older version of NFS lack the ability to discard. While not quite
as bad as the above, it's still far from ideal. Might also be worth
trying to detect? Will add something to the docs in any case.