4 # Copyright (C) 2013 Google Inc.
6 # This program is free software; you can redistribute it and/or modify
7 # it under the terms of the GNU General Public License as published by
8 # the Free Software Foundation; either version 2 of the License, or
9 # (at your option) any later version.
11 # This program is distributed in the hope that it will be useful, but
12 # WITHOUT ANY WARRANTY; without even the implied warranty of
13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 # General Public License for more details.
16 # You should have received a copy of the GNU General Public License
17 # along with this program; if not, write to the Free Software
18 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
21 """Utility functions for storage.
27 from ganeti import constants
30 def GetDiskTemplatesOfStorageType(storage_type):
31 """Given the storage type, returns a list of disk templates based on that
33 return [dt for dt in constants.DISK_TEMPLATES
34 if constants.MAP_DISK_TEMPLATE_STORAGE_TYPE[dt] == storage_type]
37 def IsDiskTemplateEnabled(disk_template, enabled_disk_templates):
38 """Checks if a particular disk template is enabled.
41 return disk_template in enabled_disk_templates
44 def IsFileStorageEnabled(enabled_disk_templates):
45 """Checks if file storage is enabled.
48 return IsDiskTemplateEnabled(constants.DT_FILE, enabled_disk_templates)
51 def IsSharedFileStorageEnabled(enabled_disk_templates):
52 """Checks if shared file storage is enabled.
55 return IsDiskTemplateEnabled(constants.DT_SHARED_FILE, enabled_disk_templates)
58 def IsLvmEnabled(enabled_disk_templates):
59 """Check whether or not any lvm-based disk templates are enabled."""
60 return len(constants.DTS_LVM & set(enabled_disk_templates)) != 0
63 def LvmGetsEnabled(enabled_disk_templates, new_enabled_disk_templates):
64 """Checks whether lvm was not enabled before, but will be enabled after
68 if IsLvmEnabled(enabled_disk_templates):
70 return len(constants.DTS_LVM & set(new_enabled_disk_templates)) != 0
73 def _GetDefaultStorageUnitForDiskTemplate(cfg, disk_template):
74 """Retrieves the identifier of the default storage entity for the given
77 @type cfg: C{objects.ConfigData}
78 @param cfg: the configuration data
79 @type disk_template: string
80 @param disk_template: a disk template, for example 'drbd'
82 @return: identifier for a storage unit, for example the vg_name for lvm
86 storage_type = constants.MAP_DISK_TEMPLATE_STORAGE_TYPE[disk_template]
87 cluster = cfg.GetClusterInfo()
88 if disk_template in constants.DTS_LVM:
89 return (storage_type, cfg.GetVGName())
90 elif disk_template == constants.DT_FILE:
91 return (storage_type, cluster.file_storage_dir)
92 elif disk_template == constants.DT_SHARED_FILE:
93 return (storage_type, cluster.shared_file_storage_dir)
95 return (storage_type, None)
98 def _GetDefaultStorageUnitForSpindles(cfg):
99 """Creates a 'spindle' storage unit, by retrieving the volume group
100 name and associating it to the lvm-pv storage type.
102 @rtype: (string, string)
103 @return: tuple (storage_type, storage_key), where storage type is
104 'lvm-pv' and storage_key the name of the default volume group
107 return (constants.ST_LVM_PV, cfg.GetVGName())
110 def GetStorageUnitsOfCluster(cfg, include_spindles=False):
111 """Examines the cluster's configuration and returns a list of storage
112 units and their storage keys, ordered by the order in which they
115 @type cfg: L{config.ConfigWriter}
116 @param cfg: Cluster configuration
117 @type include_spindles: boolean
118 @param include_spindles: flag to include an extra storage unit for physical
120 @rtype: list of tuples (string, string)
121 @return: list of storage units, each storage unit being a tuple of
122 (storage_type, storage_key); storage_type is in
123 C{constants.STORAGE_TYPES} and the storage_key a string to
124 identify an entity of that storage type, for example a volume group
125 name for LVM storage or a file for file storage.
128 cluster_config = cfg.GetClusterInfo()
130 for disk_template in cluster_config.enabled_disk_templates:
131 if constants.MAP_DISK_TEMPLATE_STORAGE_TYPE[disk_template]\
132 in constants.STS_REPORT:
133 storage_units.append(
134 _GetDefaultStorageUnitForDiskTemplate(cfg, disk_template))
136 included_storage_types = set([st for (st, _) in storage_units])
137 if not constants.ST_LVM_PV in included_storage_types:
138 storage_units.append(
139 _GetDefaultStorageUnitForSpindles(cfg))
144 def GetStorageUnits(cfg, disk_templates):
145 """Get the cluster's storage units for the given disk templates.
147 If any lvm-based disk template is requested, spindle information
148 is added to the request.
150 @type cfg: L{config.ConfigWriter}
151 @param cfg: Cluster configuration
152 @type disk_templates: list of string
153 @param disk_templates: list of disk templates for which the storage
154 units will be computed
155 @rtype: list of tuples (string, string)
156 @return: list of storage units, each storage unit being a tuple of
157 (storage_type, storage_key); storage_type is in
158 C{constants.STORAGE_TYPES} and the storage_key a string to
159 identify an entity of that storage type, for example a volume group
160 name for LVM storage or a file for file storage.
164 for disk_template in disk_templates:
165 if constants.MAP_DISK_TEMPLATE_STORAGE_TYPE[disk_template]\
166 in constants.STS_REPORT:
167 storage_units.append(
168 _GetDefaultStorageUnitForDiskTemplate(cfg, disk_template))
169 if len(set(disk_templates) & constants.DTS_LVM) > 0:
170 storage_units.append(
171 _GetDefaultStorageUnitForSpindles(cfg))
176 def LookupSpaceInfoByDiskTemplate(storage_space_info, disk_template):
177 """Looks up the storage space info for a given disk template.
179 @type storage_space_info: list of dicts
180 @param storage_space_info: result of C{GetNodeInfo}
181 @type disk_template: string
182 @param disk_template: disk template to get storage space info
184 @return: returns the element of storage_space_info that matches the given
188 storage_type = constants.MAP_DISK_TEMPLATE_STORAGE_TYPE[disk_template]
189 return LookupSpaceInfoByStorageType(storage_space_info, storage_type)
192 def LookupSpaceInfoByStorageType(storage_space_info, storage_type):
193 """Looks up the storage space info for a given storage type.
195 Note that this lookup can be ambiguous if storage space reporting for several
196 units of the same storage type was requested. This function is only supposed
197 to be used for legacy code in situations where it actually is unambiguous.
199 @type storage_space_info: list of dicts
200 @param storage_space_info: result of C{GetNodeInfo}
201 @type storage_type: string
202 @param storage_type: a storage type, which is included in the storage_units
205 @return: returns the element of storage_space_info that matches the given
210 for unit_info in storage_space_info:
211 if unit_info["type"] == storage_type:
215 # There is more than one storage type in the query, log a warning
216 logging.warning("Storage space information requested for"
217 " ambiguous storage type '%s'.", storage_type)