Re: [pve-devel] [PATCH storage 2/2] fix #4997: lvm: set "activation skip" flag for newly created LVs

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

Am 11.01.24 um 16:03 schrieb Friedrich Weber:
> Activating an LV creates a device-mapper device. In a cluster with a
> shared LVM VG (e.g. on top of iSCSI) where an LV is active on nodes 1
> and 2, deleting the LV on node 1 will not clean up the device-mapper
> device on node 2. If an LV with the same name is recreated later, the
> leftover device-mapper device will cause activation of that LV on node
> 2 to fail with:
> 
>> device-mapper: create ioctl on [...] failed: Device or resource busy
> 
> By default, LVM autoactivates all discovered LVs after boot, thus
> creating device-mapper device for all discovered LVs. As a result,
> certain combinations of guest removal (and thus LV removals) and node
> reboots can cause guest creation or VM live migration (which both
> entail LV activation) to fail with the above error message, see [1].
> 
> To avoid this issue in the future, adjust the LVM plugin to create new
> LVs with the "activation skip" flag. LVs with that flag are not
> activated unless `-K` is passed to the activation command. Consequently,
> new LVs will not be autoactivated after boot anymore, and removing LVs
> will not leave behind device-mapper devices on other nodes anymore.
> 
> The LVM plugin is still able to activate LVs, as it already passes
> `-K` to all activation commands.
> 
> Note that the flag is only set for newly created LVs, so LVs created
> before this patch can still trigger #4997. To avoid this, users can
> manually set the "activation skip" flag on existing LVs.
> 
> [1] https://bugzilla.proxmox.com/show_bug.cgi?id=4997
> 
> Suggested-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
> Signed-off-by: Friedrich Weber <f.weber@proxmox.com>

Reviewed-by: Fiona Ebner <f.ebner@proxmox.com>

> ---
> 
> Notes:
>     Should only be applied close to the next major release, see cover
>     letter.
> 
>  src/PVE/Storage/LVMPlugin.pm | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>