[CentOS] Resizing est4 filesystem while mounted

[Peter Eckel]

Hi Dennis, 

> The partitioning of the new disk in the guest is important because if you
> use the disk directly as a PV then this PV will also be shown on the host.
> An alternative is to modify the LVM filters in /etc/lvm/lvm.conf on the
> host to specifically not scan the LV for the new disk.
> I find it easier to create a partition though (i.e. use /dev/vda1 instead
> of /dev/vda as the PV).

Thanks for your explanation. Until now I just filteres the guests' PVs on the host on the "human interface level" by simply ignoring them, but yours is definitely the cleaner and more secure way. 

Maybe I missed something, but in what way is it easier to partition each and every LV one wants to use as a PV in a guest than to specify a proper filter in /etc/lvm/lvm.conf once? 

I use a consistent naming scheme for the lv's like

  /dev/vg_<number>/lv_virt_<hostname>

and use the filter 

  filter = [ "r|/dev/vg_\d+/lv_virt_\.*|" ]

to ignore all the guest's PVs. Is there any downside in doing that, or are there any advantages in using partitions instead of raw 'devices' for the PVs?

Best regards, 

  Peter.