我需要为 xen guest 创建 LV。只有一张70GB的磁盘。安装时，我使用默认进程而不是 LVM。我需要重新安装Ubuntu来创建LV吗？有没有更好的方法？多谢。
# vgdisplay
No volume groups found
# vgcreate vm /dev/sda1
No physical volume label read from /dev/sda1
Can't open /dev/sda1 exclusively. Mounted filesystem?
Unable to add physical volume '/dev/sda1' to volume group 'vm'.
# pvdisplay
# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda1 60G 4.2G 53G 8% /
udev 3.6G 4.0K 3.6G 1% /dev
tmpfs 1.5G 1.1M 1.5G 1% /run
none 5.0M 0 5.0M 0% /run/lock
none 3.6G 0 3.6G 0% …lvm ×1