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cc8aa53 Oct 15, 2012
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#
# Copyright (C) 2012 Red Hat, Inc. All rights reserved.
#
# This file is part of LVM2.
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation, either version 2.1 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
#
#-----------------------------
# Python example code:
#-----------------------------
import lvm
# Note: This example will create a logical unit, tag it and
# delete it, don't run this on production box!
#Dump information about PV
def print_pv(pv):
print 'PV name: ', pv.getName(), ' ID: ', pv.getUuid(), 'Size: ', pv.getSize()
#Dump some information about a specific volume group
def print_vg(vg_name):
#Open read only
vg = lvm.vgOpen(vg_name, 'r')
print 'Volume group:', vg_name, 'Size: ', vg.getSize()
#Retrieve a list of Physical volumes for this volume group
pv_list = vg.listPVs()
#Print out the physical volumes
for p in pv_list:
print_pv(p)
#Get a list of logical volumes in this volume group
lv_list = vg.listLVs()
if len(lv_list):
for l in lv_list:
print 'LV name: ', l.getName(), ' ID: ', l.getUuid()
else:
print 'No logical volumes present!'
vg.close()
#Returns the name of a vg with space available
def find_vg_with_free_space():
free_space = 0
rc = None
vg_names = lvm.listVgNames()
for v in vg_names:
vg = lvm.vgOpen(v, 'r')
c_free = vg.getFreeSize()
if c_free > free_space:
free_space = c_free
rc = v
vg.close()
return rc
#Walk through the volume groups and fine one with space in which we can
#create a new logical volume
def create_delete_logical_volume():
vg_name = find_vg_with_free_space()
print 'Using volume group ', vg_name, ' for example'
if vg_name:
vg = lvm.vgOpen(vg_name, 'w')
lv = vg.createLvLinear('python_lvm_ok_to_delete', vg.getFreeSize())
if lv:
print 'New lv, id= ', lv.getUuid()
#Create a tag
lv.addTag('Demo_tag')
#Get the tags
tags = lv.getTags()
for t in tags:
#Remove tag
lv.removeTag(t)
lv.deactivate()
#Try to rename
lv.rename("python_lvm_renamed")
print 'LV name= ', lv.getName()
lv.remove()
vg.close()
else:
print 'No free space available to create demo lv!'
if __name__ == '__main__':
#What version
print 'lvm version=', lvm.getVersion()
#Get a list of volume group names
vg_names = lvm.listVgNames()
#For each volume group display some information about each of them
for vg_i in vg_names:
print_vg(vg_i)
#Demo creating a logical volume
create_delete_logical_volume()