#
#
# Copyright (C) 2006, 2007, 2010, 2011, 2012 Google Inc.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 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
# General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
# 02110-1301, USA.
"""Utility functions for LVM.
"""
from ganeti import constants
def CheckVolumeGroupSize(vglist, vgname, minsize):
"""Checks if the volume group list is valid.
The function will check if a given volume group is in the list of
volume groups and has a minimum size.
@type vglist: dict
@param vglist: dictionary of volume group names and their size
@type vgname: str
@param vgname: the volume group we should check
@type minsize: int
@param minsize: the minimum size we accept
@rtype: None or str
@return: None for success, otherwise the error message
"""
vgsize = vglist.get(vgname, None)
if vgsize is None:
return "volume group '%s' missing" % vgname
elif vgsize < minsize:
return ("volume group '%s' too small (%s MiB required, %d MiB found)" %
(vgname, minsize, vgsize))
return None
def LvmExclusiveCheckNodePvs(pvs_info):
"""Check consistency of PV sizes in a node for exclusive storage.
@type pvs_info: list
@param pvs_info: list of L{LvmPvInfo} objects
@rtype: tuple
@return: A pair composed of: 1. a list of error strings describing the
violations found, or an empty list if everything is ok; 2. a pair
containing the sizes of the smallest and biggest PVs, in MiB.
"""
errmsgs = []
sizes = [pv.size for pv in pvs_info]
# The sizes of PVs must be the same (tolerance is constants.PART_MARGIN)
small = min(sizes)
big = max(sizes)
if LvmExclusiveTestBadPvSizes(small, big):
m = ("Sizes of PVs are too different: min=%d max=%d" % (small, big))
errmsgs.append(m)
return (errmsgs, (small, big))
def LvmExclusiveTestBadPvSizes(small, big):
"""Test if the given PV sizes are permitted with exclusive storage.
@param small: size of the smallest PV
@param big: size of the biggest PV
@return: True when the given sizes are bad, False otherwise
"""
# Test whether no X exists such that:
# small >= X * (1 - constants.PART_MARGIN) and
# big <= X * (1 + constants.PART_MARGIN)
return (small * (1 + constants.PART_MARGIN) <
big * (1 - constants.PART_MARGIN))