Use the mkvolume command to create an
empty volume from existing storage pools. You can use this command
for high availability configurations that include HyperSwap®,
but it can also be used for volumes that are not high availability.
Syntax
mkvolume [ name name ] -size disk_size [ -unit { b | kb | mb | gb | tb | pb } ] [ -iogrp { iogroup_id | iogroup_name } ] -pool { storage_pool_id | storage_pool_name } [ -cache { none | readonly | readwrite } ] [ { -thin | -compressed } ] [ -buffersize { buffer_size | buffer_percentage% } ] [ -warning { warning_capacity | warning_percentage% } ] [ -noautoexpand ] [ -grainsize { 32 | 64 | 128 | 256 } ] [ -udid udid ] -volumegroup { volumegroup_name | volumegroup_id }
Parameters
- -namename
- (Optional) Specifies the name that is used for the volume that is created. This value must be an
alphanumeric string 1 - 63 characters.
Remember: If you do not specify
-name, a unique default name such as volume1 is
used.
- -sizedisk_size
- (Required) Specifies the capacity of the volume, which is used with the value of the unit. The
default capacity is in MB. When the unit of bytes is used, all capacities must be in multiples of
512 bytes. An entire extent is reserved even if it is only partially used.
- -unitb | kb | mb | gb | tb | pb
- (Optional) Specifies the data units to use with the capacity that is specified by the
-size parameter. The default unit type is mb.
- -iogrpiogroup_id_list | iogroup_name_list
- (Optional) Specifies the I/O group that the new volume is cached in. The value can be a
colon-separated list of up to two I/O group IDs or names. If no value is specified, the caching I/O
group is selected based on the storage pool site. If you do not specify the
-iogrp parameter, the caching I/O group is selected by the system.
Important: If two I/O groups are specified, they must be in different sites, and the storage
pools that are specified must be in different sites. The order of the sites must
correspond.
If you create a HyperSwap® volume, the caching I/O
groups are selected based on the sites of the storage pools.
- -poolstorage_pool_id_list | storage_pool_name_list
- (Required) Specifies the storage pool in which to create the new volume. The value must be a
colon-separated list of up to two storage pool IDs or names.
Note: If one storage pool is specified,
a basic volume is created with one copy.
On systems with standard
topology, a mirrored volume can be created by specifying two storage pools.
On systems with a hyperswap topology, a highly
available volume can be created by specifying two storage pools in different sites.
- -cachenone | readonly | readwrite
- (Optional) Specifies the caching options for the volume. Use one of the following valid entries:
- readwrite enables the cache for the volume (default)
- readonly disables write caching but allows read caching for a volume
- none disables the cache mode for the volume
- -thin
- (Optional) Specifies that the volume is to be created with thin provisioning. You cannot specify
this parameter with -compressed. If you do not specify
-thin or -compressed, the volume that is created is fully
allocated.
- -compressed
- (Optional) Specifies that the volume is to be created compressed. If the -iogrp
parameter is not specified, the least used I/O group is used for compressed copies (considering the
subset of I/O groups that support compression).
Remember: This command fails if no I/O
groups support compression. If there are two sites, both sites must have at least one I/O group that
supports compression.
You cannot specify this parameter with -thin. If
you do not specify -thin or -compressed, the volume that
is created is fully allocated.
- -buffersizebuffer_size | buffer_percentage
- (Optional) Specifies the pool capacity the volume attempts to reserve as a buffer for
thin-provisioned and compressed volumes. You must specify either -thin or
-compressed with this parameter. The default value is 2%.
- -warningwarning_capacity | warning_percentage
- (Optional) Specifies a threshold at which a warning error log is generated for volumes. A
warning is generated when the used disk capacity on the thin-provisioned volume exceeds the
specified threshold. You must specify either -thin or
-compressed with this parameter. The default value is
80%.
- -noautoexpand
- (Optional) Specifies that the volume not automatically expand as it is written to. The available
buffer capacity decreases as the used capacity increases. The volume copy goes offline if the buffer
capacity is fully used. The buffer capacity can be increased by specifying expandvdisksize
-rsize. You must specify either -thin or
-compressed with this parameter. If you do not specify
-noautoexpand, the volume automatically expands as it is written to.
- -grainsize32 | 64 | 128 | 256
- (Optional) Sets the grain size (KB) for a thin-provisioned volume. If you are using the
thin-provisioned volume in a FlashCopy map, use the same
grain size as the map grain size for best performance. If you are using the thin-provisioned volume
directly with a host system, use a small grain size. The grain size value must be
32, 64, 128, or 256 KB. The
default is 256 KB.
- -udidudid
- (Optional) Specifies the unit number udid for the volume.
Important: The udid is an identifier that is required to support OpenVMS
hosts (no other systems use this parameter).
Valid options are a decimal number from
0 through 32767, or a hexadecimal number from 0
through 0x7FFF. A hexadecimal number must be preceded by 0x (for
example, 0x1234).
- -volumegroupvolumegroup_name | volumegroup_id
- (Optional) Specifies the volume group that a volume belongs to. The value must be an
alphanumeric string for the volume group name and the value must be a number for the volume group
ID.
Description
This
command creates an empty volume, which is a formatted (zeroed) volume,
by using storage from existing storage pools. You can also create a highly available
volume on systems with hyperswap topology.
Use the mkimagevolume command to create
a new volume by importing existing data on a managed disk.
An invocation example to create a volume in storage
pool 0
mkvolume -pool 0 -size 1000
The
detailed resulting output:
Volume, id [0], successfully created.
An invocation
example to create a HyperSwap® volume
with a hyperswap topology
mkvolume -pool site1pool:site2pool -size 200
The
detailed resulting output:
Volume, id [2], successfully created.