Package ganeti :: Package utils :: Module storage

Module storage

Utility functions for storage.

Functions

GetDiskTemplatesOfStorageTypes(*storage_types)
Given the storage type, returns a list of disk templates based on that storage type.

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IsDiskTemplateEnabled(disk_template, enabled_disk_templates)
Checks if a particular disk template is enabled.

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IsFileStorageEnabled(enabled_disk_templates)
Checks if file storage is enabled.

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IsSharedFileStorageEnabled(enabled_disk_templates)
Checks if shared file storage is enabled.

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IsLvmEnabled(enabled_disk_templates)
Check whether or not any lvm-based disk templates are enabled.

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LvmGetsEnabled(enabled_disk_templates, new_enabled_disk_templates)
Checks whether lvm was not enabled before, but will be enabled after the operation.

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string

_GetDefaultStorageUnitForDiskTemplate(cfg, disk_template)
Retrieves the identifier of the default storage entity for the given storage type.

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DiskTemplateSupportsSpaceReporting(disk_template)
Check whether the disk template supports storage space reporting.

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list of tuples (string, string)

GetStorageUnits(cfg, disk_templates)
Get the cluster's storage units for the given disk templates.

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tuple

LookupSpaceInfoByDiskTemplate(storage_space_info, disk_template)
Looks up the storage space info for a given disk template.

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tuple

LookupSpaceInfoByStorageType(storage_space_info, storage_type)
Looks up the storage space info for a given storage type.

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generator

GetDiskLabels(prefix, num_disks, start=0)
Generate disk labels for a number of disks

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tuple(string, list(string)) or NoneType

CreateBdevPartitionMapping(image_path)
Create dm device for each partition of disk image.

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ReleaseBdevPartitionMapping(loop_dev_path)
Release allocated dm devices and loopback devices.

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osminor(dev)
Return the device minor number from a raw device number.

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Imports: logging, constants, errors, utils_io, utils_process

Function Details

[hide private]

_GetDefaultStorageUnitForDiskTemplate(cfg, disk_template)

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Retrieves the identifier of the default storage entity for the given storage type.

Parameters:

cfg (objects.ConfigData) - the configuration data
disk_template (string) - a disk template, for example 'drbd'

Returns: string

identifier for a storage unit, for example the vg_name for lvm storage

GetStorageUnits(cfg, disk_templates)

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Get the cluster's storage units for the given disk templates.

If any lvm-based disk template is requested, spindle information is added to the request.

Parameters:

cfg (config.ConfigWriter) - Cluster configuration
disk_templates (list of string) - list of disk templates for which the storage units will be computed

Returns: list of tuples (string, string)

list of storage units, each storage unit being a tuple of (storage_type, storage_key); storage_type is in constants.STORAGE_TYPES and the storage_key a string to identify an entity of that storage type, for example a volume group name for LVM storage or a file for file storage.

LookupSpaceInfoByDiskTemplate(storage_space_info, disk_template)

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Looks up the storage space info for a given disk template.

Parameters:

storage_space_info (list of dicts) - result of GetNodeInfo
disk_template (string) - disk template to get storage space info

Returns: tuple

returns the element of storage_space_info that matches the given disk template

LookupSpaceInfoByStorageType(storage_space_info, storage_type)

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Looks up the storage space info for a given storage type.

Note that this lookup can be ambiguous if storage space reporting for several units of the same storage type was requested. This function is only supposed to be used for legacy code in situations where it actually is unambiguous.

Parameters:

storage_space_info (list of dicts) - result of GetNodeInfo
storage_type (string) - a storage type, which is included in the storage_units list

Returns: tuple

returns the element of storage_space_info that matches the given storage type

GetDiskLabels(prefix, num_disks, start=0)

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Generate disk labels for a number of disks

Note that disk labels are generated in the range [start..num_disks[ (e.g., as in range(start, num_disks))

Parameters:

prefix (string) - disk label prefix (e.g., "/dev/sd")
num_disks (int) - number of disks (i.e., disk labels)
start (int) - optional start index

Returns: generator

generator for the disk labels

CreateBdevPartitionMapping(image_path)

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Create dm device for each partition of disk image.

This operation will allocate a loopback and a device-mapper device to map partitions. You must call ReleaseBdevPartitionMapping to clean up resources allocated by this function call.

Parameters:

image_path (string) - path of multi-partition disk image

Returns: tuple(string, list(string)) or NoneType

returns the tuple(loopback_device, list(device_mapper_files)) if image_path is a multi-partition disk image. otherwise, returns None.

ReleaseBdevPartitionMapping(loop_dev_path)

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Release allocated dm devices and loopback devices.

Parameters:

loop_dev_path (string) - path of loopback device returned by CreateBdevPartitionMapping

osminor(dev)

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Return the device minor number from a raw device number.

This is a replacement for os.minor working around the issue that Python's os.minor still has the old definition. See Ganeti issue 1058 for more details.