VDO: libblockdev Reference Manual

VDO

VDO — DEPRECATED plugin for operations with VDO devices

Functions

gboolean	bd_vdo_check_deps ()
gboolean	bd_vdo_init ()
void	bd_vdo_close ()
GQuark	bd_vdo_error_quark ()
const gchar *	bd_vdo_get_write_policy_str ()
BDVDOWritePolicy	bd_vdo_get_write_policy_from_str ()
BDVDOInfo *	bd_vdo_info ()
gboolean	bd_vdo_create ()
gboolean	bd_vdo_remove ()
gboolean	bd_vdo_change_write_policy ()
gboolean	bd_vdo_enable_compression ()
gboolean	bd_vdo_disable_compression ()
gboolean	bd_vdo_enable_deduplication ()
gboolean	bd_vdo_disable_deduplication ()
gboolean	bd_vdo_activate ()
gboolean	bd_vdo_deactivate ()
gboolean	bd_vdo_start ()
gboolean	bd_vdo_stop ()
gboolean	bd_vdo_grow_logical ()
gboolean	bd_vdo_grow_physical ()
BDVDOStats *	bd_vdo_get_stats ()
GHashTable *	bd_vdo_get_stats_full ()
gboolean	bd_vdo_is_tech_avail ()

Types and Values

enum	BDVDOError
#define	BD_VDO_ERROR
	BDVDOInfo
	BDVDOStats
enum	BDVDOTech
enum	BDVDOTechMode

Includes

#include <vdo.h>

Description

A plugin for operations with VDO devices.

This plugin has been deprecated since version 2.24 and should not be used in newly-written code. Use LVM-VDO integration instead.

Functions

bd_vdo_check_deps ()

gboolean
bd_vdo_check_deps (void);

bd_vdo_check_deps has been deprecated since version 2.24 and should not be used in newly-written code.

Use LVM-VDO integration instead.

Returns

whether the plugin's runtime dependencies are satisfied or not

Function checking plugin's runtime dependencies.

bd_vdo_init ()

gboolean
bd_vdo_init (void);

bd_vdo_init has been deprecated since version 2.24 and should not be used in newly-written code.

Use LVM-VDO integration instead.

Initializes the plugin. **This function is called automatically by the library's initialization functions.**

bd_vdo_close ()

void
bd_vdo_close (void);

bd_vdo_close has been deprecated since version 2.24 and should not be used in newly-written code.

Use LVM-VDO integration instead.

Cleans up after the plugin. **This function is called automatically by the library's functions that unload it.**

bd_vdo_error_quark ()

GQuark
bd_vdo_error_quark (void);

[skip]

bd_vdo_get_write_policy_str ()

const gchar *
bd_vdo_get_write_policy_str (BDVDOWritePolicy policy,
                             GError **error);

bd_vdo_get_write_policy_str has been deprecated since version 2.24 and should not be used in newly-written code.

Use LVM-VDO integration instead.

Parameters

policy	policy to get the string representation for
error	place to store error (if any).	[out]

Returns

string representation of policy or NULL in case of error

Tech category: always provided/supported

bd_vdo_get_write_policy_from_str ()

BDVDOWritePolicy
bd_vdo_get_write_policy_from_str (const gchar *policy_str,
                                  GError **error);

bd_vdo_get_write_policy_from_str has been deprecated since version 2.24 and should not be used in newly-written code.

Use LVM-VDO integration instead.

Parameters

policy_str	string representation of a write policy mode
error	place to store error (if any).	[out]

Returns

write policy for the mode_str or BD_VDO_WRITE_POLICY_UNKNOWN if failed to determine

Tech category: always provided/supported

bd_vdo_info ()

BDVDOInfo *
bd_vdo_info (const gchar *name,
             GError **error);

bd_vdo_info has been deprecated since version 2.24 and should not be used in newly-written code.

Use LVM-VDO integration instead.

Parameters

name	a VDO volume to get information about
error	place to store error (if any).	[out]

Returns

information about the VDO volume or NULL in case of error (error gets populated in those cases)

Tech category: BD_VDO_TECH_VDO-BD_VDO_TECH_MODE_QUERY.

[transfer full]

bd_vdo_create ()

gboolean
bd_vdo_create (const gchar *name,
               const gchar *backing_device,
               guint64 logical_size,
               guint64 index_memory,
               gboolean compression,
               gboolean deduplication,
               BDVDOWritePolicy write_policy,
               const BDExtraArg **extra,
               GError **error);

bd_vdo_create has been deprecated since version 2.24 and should not be used in newly-written code.

Use LVM-VDO integration instead.

Parameters

name	name for the VDO volume
backing_device	device to use for VDO storage
logical_size	logical VDO volume size or 0 for default (size of `backing_device` )
index_memory	amount of index memory or 0 for default; note that only some sizes are valid here (0.25, 0.5 and 0.75 GB and integer multiples of 1 GB) invalid sizes will be rounded DOWN to nearest GB (or one of the allowed decimal values)
compression	whether to enable compression or not
deduplication	whether to enable deduplication or not
write_policy	write policy for the volume
extra	extra options for the VDO creation (just passed to VDO as is).	[allow-none][array zero-terminated=1]
error	place to store error (if any).	[out]

Returns

whether the VDO volume was successfully created or not

Tech category: BD_VDO_TECH_VDO-BD_VDO_TECH_MODE_CREATE

bd_vdo_remove ()

gboolean
bd_vdo_remove (const gchar *name,
               gboolean force,
               const BDExtraArg **extra,
               GError **error);

bd_vdo_remove has been deprecated since version 2.24 and should not be used in newly-written code.

Use LVM-VDO integration instead.

Parameters

name	name of an existing VDO volume
force	force remove the volume
extra	extra options for the VDO creation (just passed to VDO as is).	[allow-none][array zero-terminated=1]
error	place to store error (if any).	[out]

Returns

whether the VDO volume was successfully removed or not

Tech category: BD_VDO_TECH_VDO-BD_VDO_TECH_MODE_MODIFY

bd_vdo_change_write_policy ()

gboolean
bd_vdo_change_write_policy (const gchar *name,
                            BDVDOWritePolicy write_policy,
                            const BDExtraArg **extra,
                            GError **error);

bd_vdo_change_write_policy has been deprecated since version 2.24 and should not be used in newly-written code.

Use LVM-VDO integration instead.

Parameters

name	name of an existing VDO volume
write_policy	new write policy for the volume
extra	extra options for the VDO creation (just passed to VDO as is).	[allow-none][array zero-terminated=1]
error	place to store error (if any).	[out]

Returns

whether the policy was successfully changed or not

Tech category: BD_VDO_TECH_VDO-BD_VDO_TECH_MODE_MODIFY

bd_vdo_enable_compression ()

gboolean
bd_vdo_enable_compression (const gchar *name,
                           const BDExtraArg **extra,
                           GError **error);

bd_vdo_enable_compression has been deprecated since version 2.24 and should not be used in newly-written code.

Use LVM-VDO integration instead.

Parameters

name	name of an existing VDO volume
extra	extra options for the VDO creation (just passed to VDO as is).	[allow-none][array zero-terminated=1]
error	place to store error (if any).	[out]

Returns

whether the compression was successfully enabled or not

Tech category: BD_VDO_TECH_VDO-BD_VDO_TECH_MODE_MODIFY

bd_vdo_disable_compression ()

gboolean
bd_vdo_disable_compression (const gchar *name,
                            const BDExtraArg **extra,
                            GError **error);

bd_vdo_disable_compression has been deprecated since version 2.24 and should not be used in newly-written code.

Use LVM-VDO integration instead.

Parameters

name	name of an existing VDO volume
extra	extra options for the VDO creation (just passed to VDO as is).	[allow-none][array zero-terminated=1]
error	place to store error (if any).	[out]

Returns

whether the compression was successfully disabled or not

Tech category: BD_VDO_TECH_VDO-BD_VDO_TECH_MODE_MODIFY

bd_vdo_enable_deduplication ()

gboolean
bd_vdo_enable_deduplication (const gchar *name,
                             const BDExtraArg **extra,
                             GError **error);

bd_vdo_enable_deduplication has been deprecated since version 2.24 and should not be used in newly-written code.

Use LVM-VDO integration instead.

Parameters

name	name of an existing VDO volume
extra	extra options for the VDO creation (just passed to VDO as is).	[allow-none][array zero-terminated=1]
error	place to store error (if any).	[out]

Returns

whether the deduplication was successfully enabled or not

Tech category: BD_VDO_TECH_VDO-BD_VDO_TECH_MODE_MODIFY

bd_vdo_disable_deduplication ()

gboolean
bd_vdo_disable_deduplication (const gchar *name,
                              const BDExtraArg **extra,
                              GError **error);

bd_vdo_disable_deduplication has been deprecated since version 2.24 and should not be used in newly-written code.

Use LVM-VDO integration instead.

Parameters

name	name of an existing VDO volume
extra	extra options for the VDO creation (just passed to VDO as is).	[allow-none][array zero-terminated=1]
error	place to store error (if any).	[out]

Returns

whether the deduplication was successfully disabled or not

Tech category: BD_VDO_TECH_VDO-BD_VDO_TECH_MODE_MODIFY

bd_vdo_activate ()

gboolean
bd_vdo_activate (const gchar *name,
                 const BDExtraArg **extra,
                 GError **error);

bd_vdo_activate has been deprecated since version 2.24 and should not be used in newly-written code.

Use LVM-VDO integration instead.

Parameters

name	name of an existing VDO volume
extra	extra options for the VDO creation (just passed to VDO as is).	[allow-none][array zero-terminated=1]
error	place to store error (if any).	[out]

Returns

whether the VDO volume was successfully activated or not

Tech category: BD_VDO_TECH_VDO-BD_VDO_TECH_MODE_ACTIVATE_DEACTIVATE

bd_vdo_deactivate ()

gboolean
bd_vdo_deactivate (const gchar *name,
                   const BDExtraArg **extra,
                   GError **error);

bd_vdo_deactivate has been deprecated since version 2.24 and should not be used in newly-written code.

Use LVM-VDO integration instead.

Parameters

name	name of an existing VDO volume
extra	extra options for the VDO creation (just passed to VDO as is).	[allow-none][array zero-terminated=1]
error	place to store error (if any).	[out]

Returns

whether the VDO volume was successfully deactivated or not

Tech category: BD_VDO_TECH_VDO-BD_VDO_TECH_MODE_ACTIVATE_DEACTIVATE

bd_vdo_start ()

gboolean
bd_vdo_start (const gchar *name,
              gboolean rebuild,
              const BDExtraArg **extra,
              GError **error);

bd_vdo_start has been deprecated since version 2.24 and should not be used in newly-written code.

Use LVM-VDO integration instead.

Parameters

name	name of an existing VDO volume
rebuild	force rebuild the volume
extra	extra options for the VDO creation (just passed to VDO as is).	[allow-none][array zero-terminated=1]
error	place to store error (if any).	[out]

Returns

whether the VDO volume was successfully started or not

Tech category: BD_VDO_TECH_VDO-BD_VDO_TECH_MODE_START_STOP

bd_vdo_stop ()

gboolean
bd_vdo_stop (const gchar *name,
             gboolean force,
             const BDExtraArg **extra,
             GError **error);

bd_vdo_stop has been deprecated since version 2.24 and should not be used in newly-written code.

Use LVM-VDO integration instead.

Parameters

name	name of an existing VDO volume
force	force stop the volume
extra	extra options for the VDO creation (just passed to VDO as is).	[allow-none][array zero-terminated=1]
error	place to store error (if any).	[out]

Returns

whether the VDO volume was successfully stopped or not

Tech category: BD_VDO_TECH_VDO-BD_VDO_TECH_MODE_START_STOP

bd_vdo_grow_logical ()

gboolean
bd_vdo_grow_logical (const gchar *name,
                     guint64 size,
                     const BDExtraArg **extra,
                     GError **error);

bd_vdo_grow_logical has been deprecated since version 2.24 and should not be used in newly-written code.

Use LVM-VDO integration instead.

Parameters

name	name of an existing VDO volume
size	new logical size for the volume
extra	extra options for the VDO creation (just passed to VDO as is).	[allow-none][array zero-terminated=1]
error	place to store error (if any).	[out]

Returns

whether the VDO volume was successfully resized or not

Tech category: BD_VDO_TECH_VDO-BD_VDO_TECH_MODE_GROW

bd_vdo_grow_physical ()

gboolean
bd_vdo_grow_physical (const gchar *name,
                      const BDExtraArg **extra,
                      GError **error);

bd_vdo_grow_physical has been deprecated since version 2.24 and should not be used in newly-written code.

Use LVM-VDO integration instead.

Parameters

name	name of an existing VDO volume
extra	extra options for the VDO tool (just passed to VDO as is).	[allow-none][array zero-terminated=1]
error	place to store error (if any).	[out]

Returns

whether the VDO volume was successfully grown or not

Tech category: BD_VDO_TECH_VDO-BD_VDO_TECH_MODE_GROW

bd_vdo_get_stats ()

BDVDOStats *
bd_vdo_get_stats (const gchar *name,
                  GError **error);

bd_vdo_get_stats has been deprecated since version 2.24 and should not be used in newly-written code.

Use LVM-VDO integration instead.

Parameters

name	name of an existing VDO volume
error	place to store error (if any).	[out]

Returns

a structure containing selected statistics or NULL in case of error (error gets populated in those cases)

In contrast to bd_vdo_get_stats_full this function will only return selected statistics in a fixed structure. In case a value is not available, -1 would be returned.

The following statistics are presented:

"block_size": The block size of a VDO volume, in bytes.
"logical_block_size": The logical block size, in bytes.
"physical_blocks": The total number of physical blocks allocated for a VDO volume.
"data_blocks_used": The number of physical blocks currently in use by a VDO volume to store data.
"overhead_blocks_used": The number of physical blocks currently in use by a VDO volume to store VDO metadata.
"logical_blocks_used": The number of logical blocks currently mapped.
"usedPercent": The percentage of physical blocks used on a VDO volume (= used blocks / allocated blocks * 100).
"savingPercent": The percentage of physical blocks saved on a VDO volume (= [logical blocks used - physical blocks used] / logical blocks used).
"writeAmplificationRatio": The average number of block writes to the underlying storage per block written to the VDO device.

Tech category: BD_VDO_TECH_VDO-BD_VDO_TECH_MODE_QUERY.

[transfer full]

bd_vdo_get_stats_full ()

GHashTable *
bd_vdo_get_stats_full (const gchar *name,
                       GError **error);

bd_vdo_get_stats_full has been deprecated since version 2.24 and should not be used in newly-written code.

Use LVM-VDO integration instead.

Parameters

name	name of an existing VDO volume
error	place to store error (if any).	[out]

Returns

hashtable of type string - string of available statistics or NULL in case of error (error gets populated in those cases)

Statistics are collected from the values exposed by the kernel kvdo module at the /sys/kvdo/<VDO_NAME>/statistics/ path. Some of the keys are computed to mimic the information produced by the vdo tools. Please note the contents of the hashtable may vary depending on the actual kvdo module version.

Tech category: BD_VDO_TECH_VDO-BD_VDO_TECH_MODE_QUERY.

[transfer full][element-type utf8 utf8]

bd_vdo_is_tech_avail ()

gboolean
bd_vdo_is_tech_avail (BDVDOTech tech,
                      guint64 mode,
                      GError **error);

bd_vdo_is_tech_avail has been deprecated since version 2.24 and should not be used in newly-written code.

Use LVM-VDO integration instead.

Parameters

tech	the queried tech
mode	a bit mask of queried modes of operation (BDVDOTechMode) for `tech`
error	place to store error (details about why the `tech` -`mode` combination is not available).	[out]

Returns

whether the tech -mode combination is available -- supported by the plugin implementation and having all the runtime dependencies available

Types and Values

enum BDVDOError

Members

BD_VDO_ERROR_FAIL
BD_VDO_ERROR_PARSE
BD_VDO_ERROR_TECH_UNAVAIL
BD_VDO_ERROR_POLICY_INVAL

BD_VDO_ERROR

#define             BD_VDO_ERROR

BDVDOInfo

typedef struct {
    gchar *name;
    gchar *device;
    gboolean active;
    gboolean deduplication;
    gboolean compression;
    guint64 logical_size;
    guint64 physical_size;
    guint64 index_memory;
    BDVDOWritePolicy write_policy;
} BDVDOInfo;

BDVDOInfo has been deprecated since version 2.24 and should not be used in newly-written code.

Use LVM-VDO integration instead.

Members

gchar *`name`;	name of the VDO volume
gchar *`device`;	underlying block device
gboolean `active`;	whether the volume is active or not
gboolean `deduplication`;	whether deduplication is enabled
gboolean `compression`;	whether compression is enabled
guint64 `logical_size`;	logical size of the volume
guint64 `physical_size`;	sphysical size of the volume
guint64 `index_memory`;	index memory size
BDVDOWritePolicy `write_policy`;	write policy of the volume

BDVDOStats

typedef struct {
    gint64 block_size;
    gint64 logical_block_size;
    gint64 physical_blocks;
    gint64 data_blocks_used;
    gint64 overhead_blocks_used;
    gint64 logical_blocks_used;
    gint64 used_percent;
    gint64 saving_percent;
    gdouble write_amplification_ratio;
} BDVDOStats;

BDVDOStats has been deprecated since version 2.24 and should not be used in newly-written code.

Use LVM-VDO integration instead.

Members

gint64 `block_size`;	block size of a VDO volume, in bytes
gint64 `logical_block_size`;	logical block size, in bytes
gint64 `physical_blocks`;	total number of physical blocks allocated
gint64 `data_blocks_used`;	number of physical blocks currently in use to store data
gint64 `overhead_blocks_used`;	number of physical blocks currently in use to store VDO metadata
gint64 `logical_blocks_used`;	number of logical blocks currently mapped
gint64 `used_percent`;	percentage of physical blocks used
gint64 `saving_percent`;	percentage of physical blocks saved
gdouble `write_amplification_ratio`;	average number of block writes to the underlying storage per block written

enum BDVDOTech

Members

BD_VDO_TECH_VDO

enum BDVDOTechMode

Members

BD_VDO_TECH_MODE_CREATE
BD_VDO_TECH_MODE_REMOVE
BD_VDO_TECH_MODE_MODIFY
BD_VDO_TECH_MODE_ACTIVATE_DEACTIVATE
BD_VDO_TECH_MODE_START_STOP
BD_VDO_TECH_MODE_QUERY
BD_VDO_TECH_MODE_GROW