Hi-

Is it safe to use the zerofree utility on an ext4 partition inside an LVM with guestfish?  I know zerofree works on ext4, but I am unsure about LVM.  The info page uses the syntax “zerofree <device>”, so using the info page example, could I (safely) do something like the following?

$ guestfish

 Welcome to guestfish, the libguestfs filesystem interactive shell for

editing virtual machine filesystems.

 Type: 'help' for a list of commands

       'man' to read the manual

       'quit' to quit the shell

 ><fs> add disk.img

><fs> run

><fs> list-filesystems

/dev/sda1: ext4

/dev/vg_guest/lv_root: ext4

/dev/vg_guest/lv_swap: swap

><fs> zerofree /dev/vg_guest/lv_root

Thanks for any light you can shed on this.

-Ben