Use the addvdiskcopy command to add a copy to an existing volume,
which changes a nonmirrored volume into a mirrored volume. On a system with a hyperswap
topology, use the addvolumecopy command to convert an existing volume to a HyperSwap volume by adding a copy at a second
site.
Note: The first syntax diagram depicts the addition of a sequential or striped mode volume.
The second syntax diagram depicts the addition of an image mode volume.
Syntax
addvdiskcopy -mdiskgrp { mdisk_group_id_list | mdisk_group_name_list } [ -mirrorwritepriority { latency | redundancy } ] [ -vtype { seq | striped } ] [ -mdisk { mdisk_id_list | mdisk_name_list } ] [ -rsize { disk_size | disk_size_percentage% | auto } [ -warning { disk_size | disk_size_percentage% } ] [ -autoexpand ] ] [ -rsize (cont.) { [ -grainsize { 32 | 64 | 128 | 256 } ] } [ -compressed ] [ -deduplicated ] ] [ -createsync ] [ -syncrate syncrate ] [ -unit { b | kb | mb | gb | tb | pb } ] [ -easytier { on | off } ] { vdisk_name | vdisk_id }
addvdiskcopy [ -mirrorwritepriority { latency | redundancy } ] -mdiskgrp { mdisk_group_id_list | mdisk_group_name_list } -vtype { image } -mdisk { mdisk_id_list | mdisk_name_list } [ -rsize { disk_size | disk_size_percentage% | auto } [ -warning { disk_size | disk_size_percentage% } ] [ -autoexpand ] ] [ -rsize (cont.) { [ -grainsize { 32 | 64 | 128 | 256 } ] } [ -compressed ] [ -import ] [ -deduplicated ] ] [ -createsync ] [ -syncrate syncrate ] [ -unit { b | kb | mb | gb | tb | pb } ] -tier { tier0_flash | tier1_flash | tier_enterprise | tier_nearline } [ -easytier { on | off } ] [ -autodelete ] [ -deduplicated ] { vdisk_name | vdisk_id }
Parameters
- -mdiskgrpmdisk_group_id_list | mdisk_group_name_list
- (Required) Specifies the storage pools to use to create copies for the volume. You must specify
a group for each copy that is being added.
Note: If the MDisk group is from a child pool,
-vtype must be striped.
- -mirrorwriteprioritylatency | redundancy
- (Optional) Specifies how to configure the mirror write algorithm priority.
- Choosing latency means a copy that is slow to respond to a write input/output
(I/O) becomes unsynchronized, and the write I/O completes if the other copy successfully writes the
data.
- Choosing redundancy means a copy that is slow to respond to a write I/O
synchronizes completion of the write I/O with the completion of the slower I/O to maintain
synchronization.
- -vtypeseq | striped | image
- (Optional) Specifies the virtualization type for the copy: sequential, striped, or image. The
type can be different than the virtualization types for other copies on the volume. The default
virtualization type is striped. If you specify the -rsize
auto option or the -import option, you must also specify the
-vtype image option.
Note: You
cannot create an image or sequential mode copy from a child pool or data reduction
pools.
- -mdiskmdisk_id_list | mdisk_name_list
- (Optional) Specifies one or more managed disks (MDisks). For sequential and image mode copies,
you must specify a single MDisk that has sufficient free extents. For image mode copies, the MDisk
must be in unmanaged mode. For sequential mode copies the MDisk must be in the managed mode.
- -syncratesyncrate
- (Optional) Specifies the copy synchronization rate. A value of zero prevents synchronization.
For the supported -syncrate values and their corresponding rates, see
Relationship between the syncrate value and the data copied per second.
If not specified, the current value is
unchanged.
- -createsync
- (Optional) Suppresses the synchronization of the new volume copy with the primary copy. Using
this parameter can cause data corruption if the primary copy fails and leaves an unsynchronized
secondary copy to provide data. Using this parameter can cause loss of read stability in unwritten
areas if the primary copy fails, data is read from the primary copy, and then different data is read
from the secondary copy.
Note: You cannot specify -createsync for a volume that
is fast formatting.
- -rsizedisk_size | disk_size_percentage% | auto
- (Optional) Makes the copy thin-provisioned and specifies the real size of the copy. Specify the
disk_size | disk_size_percentage value by using an integer, or an integer
immediately followed by the percent character (%). The default units for
disk_size are megabytes (MB). To specify different units, use the
-unit parameter. The auto option creates a
volume copy that uses the entire size of the MDisk; if you specify the -rsize
auto option, you must also specify the -vtype image
option.
- -deduplicated
- (Optional) Adds a deduplicated volume. If you specify -deduplicated, you
must also specify -rsize because it applies only to thin-provisioned or
compressed volumes.
Note: Data deduplication works only with data reduction storage pools. You can
only create deduplicated volumes and volume copies in an I/O group if no compressed volumes or
volume copies exist in regular storage pools.
- -compressed
- (Optional) Adds exactly one copy to an existing volume that already has (only) one copy a
volume, and enables compression. Requires the -rsize parameter also be
specified.
Remember: - You cannot specify this parameter with the -grainsize parameter.
- When you specify this parameter with the -import parameter, you must
specify -rsize auto.
- -warningdisk_size | disk_size_percentage%
- (Optional) Requires that the -rsize parameter also be specified.
Generates a warning when the used disk capacity on the thin-provisioned copy first exceeds the
specified threshold. You can specify a disk_size integer, which defaults
to megabytes (MB) unless the -unit parameter is specified; or you can
specify a disk_size%, which is a percentage of the volume size.
If -autoexpand is enabled, the default value for
-warning is 80% of the volume capacity. If
-autoexpand is not enabled, the default value for warning is 80% of the
real capacity. To disable warnings, specify 0.
- -autoexpand
- (Optional) Requires that the -rsize parameter also be specified.
Specifies that thin-provisioned copies automatically expand their real capacities by allocating new
extents from their storage pool. If the -autoexpand parameter is
specified, the -rsize parameter specifies a capacity that is reserved by
the copy. It protects the copy from going offline when its storage pool runs out of space by
allowing it to consume this reserved space first.
- -grainsize32 | 64 | 128 | 256
- (Optional) Requires that the -rsize parameter also be specified. Sets
the grain size (KB) for a thin-provisioned volume copy. The grain size value must be 32, 64, 128, or
256 KB. The default is 256 KB.
- -unitb | kb | mb | gb | tb | pb
- (Optional) Specifies the data units for the -rsize and
-warning parameters.
- -import
- (Optional) Imports an image mode disk that contains a thin-provisioned volume into the system.
Requires that the -rsize and -vtypeimage parameters also be specified.
- -tiertier0_flash | tier1_flash | tier_enterprise |
tier_nearline
- (Optional) Specifies the MDisk tier when an image mode copy is added.
- tier0_flash
- Specifies a tier0_flash hard disk drive or an external MDisk for the newly
discovered or external volume.
- tier1_flash
- Specifies a tier1_flash (or flash drive) hard disk drive or an external MDisk
for the newly discovered or external volume.
- tier_enterprise
- Specifies a tier_enterprise hard disk drive or an external MDisk for the newly
discovered or external volume.
- tier_nearline
- Specifies a tier_nearline hard disk drive or an external MDisk for the newly
discovered or external volume.
- -easytieron | off
- (Optional) Determines whether the Easy Tier function is allowed to move
extents for this volume. If a volume copy is striped and not being migrated, see the settings in
this table.
If the volume copy is in image or sequential mode or is being migrated, the
volume copy Easy Tier status is
measured instead of active.
The default Easy Tier setting for a storage
pool is auto, and the default Easy Tier setting for a volume copy is on. If the setting is
on, it means that Easy Tier
functions except pool performance balancing are disabled for storage pools with a single tier, and
that automatic data placement mode is enabled for all striped volume copies in a storage pool with
two or more tiers.
- -autodelete
- (Optional) Specifies the primary copy is deleted after the secondary copy is synchronized.
- jvdisk_name | vdisk_id
- (Required) Specifies the volume to add the volume copy to, either by ID or by name.
Description
The addvdiskcopy command adds a copy to an existing volume, which changes a
nonmirrored volume into a mirrored volume. Use the mkdiskgrp parameter to specify
the storage pools that provide storage for the copy; the lsmdiskgrp command
lists the available storage pools and the amount of available storage in each group.
The
addvdiskcopy command can be specified with a file system volume, but must be used
with the same storage pool for that volume.
Remember: Only compressed copies are allowed
to be added to file system volumes.
The
addvdiskcopy command adds a
different volume copy, such as a copy created from an uncompressed to compressed conversion or a
compressed to uncompressed conversion.
Note: A volume cannot have volume copies in different
storage pools if cloud snapshot is enabled on the volume.
A thin-provisioned or compressed volume copy in a data reduction storage pool
must not be a sequential or image mode volume. On some node types, you can create a compressed
volume copy in a data reduction storage pool for an I/O group. A compressed volume copy in a data
reduction pool can only be created in an I/O group with V5030, V7000, or SVC node types. You can
create thin-provisioned volume copies on any node type. Use the
-autoexpandparameter to create thin-provisioned or compressed volume copies
from a data reduction storage pool. Volumes can also have fully allocated volume copies in data
reduction storage pools.
Compressed volumes/copies cannot be created if the I/O group in
which the copy is being created supports only software compression and:
- The I/O group already has Real-time compression copies and the copy is data reduction.
- The I/O group already has data reduction copies and the copy uses Real-time compression.
You cannot create a volume copy that is a thin-provisioned or compressed
volume in a data reduction storage pool, and the volume caching mode is none or
readonly. You must specify chvdisk to change the volume caching
mode to readwrite.
You cannot specify -warning for a thin-provisioned or
compressed volume copy in a data reduction storage pool.
For thin-provisioned and compressed volume copies in data reduction storage
pools, the Easy Tier mode for the volume is taken from
the data reduction storage pool. The Easy Tier mode
cannot be configured on these volume types.
You cannot specify -grainsize for thin-provisioned and
compressed volume copies in data reduction storage pools. This type of volume copy is created with a
size of 8 KB.
Thin-provisioned or compressed volume copies in data reduction pools cannot be
created if the data reduction storage pool is offline and requires recovery. If the recovery is
still in progress, you must wait until the recovery is complete and the pool is in
online state.
An
encryption key cannot be used when you add an image mode MDisk. To use encryption (when the MDisk
has an encryption key), the MDisk must be self-encrypting.
Remember: You cannot add a volume copy if the volume to be copied is being
formatted.
The virtualization types are defined as follows:
- sequential (seq)
- This policy requires the -mdisk parameter with a single managed disk as its
argument. This MDisk must be in the managed mode.
It creates the volume by using extents from the
given managed disk (assuming enough free extents exist on the managed disk).
- striped
- The striped policy is the default policy. If the -vtype
parameter is not specified, this policy is used in its default form. That is, all managed disks in
the storage pool are used to create the volume. The striping is at an extent level; one extent from
each managed disk in the group is used. For example, a storage pool with 10 managed disks uses one
extent from each managed disk, then it uses the 11th extent from the first managed disk, and so on.
If the -mdisk parameter is also specified, you can supply a list of managed
disks to use as the stripe set. This list can include two or more managed disks from the same
storage pool. The same circular algorithm is used across the striped set. However, a single managed
disk can be specified more than once in the list. For example, if you enter -m
0:1:2:1, the extents are from the following managed disks: 0, 1, 2, 1, 0, 1, 2, and so
forth. All MDisks that are specified in the -mdisk parameter must be in managed
mode.
- image
- This policy allows image mode volumes to be created when a managed disk already has data on it,
perhaps from a previrtualized subsystem. When an image mode volume is created, it directly
corresponds to the (previously unmanaged) managed disk that it was created from; therefore, volume
logical block address (LBA) x equals managed disk LBA i. You
can use this command to bring a nonvirtualized disk under the control of the system. After it is
under the control of the system, you can migrate the volume from the single managed disk. When it is
migrated, the volume is no longer an image mode volume.
You can add image mode volumes to an
already populated storage pool with other types of volumes, such as a striped or sequential.
Note: An image mode copy must be at least as large as the volume that it is being added to, but
any capacity beyond the size of the volume is not accessible.
The command returns the ID of the newly created volume copy.
Create the first compressed
volume copy for an I/O group to activate compression. You cannot create or move a compressed volume
copy to an I/O group that contains (at least) one node that does not support compressed volumes. You
must use another I/O group, but note that it does not affect moving to the recovery I/O
group.
Important: - If the volume (or volume copy) is a target of a FlashCopy mapping with a source volume in an active-active relationship, the
new storage pool must be in the same site as the source volume.
- If this command is used for a volume that is a master volume, an auxiliary volume, or a change
volume of an active-active relationship, the new copy must be created in a storage
pool of the same site as the existing volume copy.
- When you add an image mode copy, the site information for the MDisk being added must be
well-defined and match the site information for any other MDisks in the storage pool.
The rate at which the volume copies resynchronize after loss of synchronization can be specified
by using the
-syncrate parameter. This table provides the relationship of the
syncrate value to the data copied per second.
Note: These settings also affect
the initial rate of formatting.
Table 2. Relationship between the syncrate value
and the data copied per second
User-specified syncrate attribute
value |
Data copied/sec |
1 - 10 |
128 KB |
11 - 20 |
256 KB |
21 - 30 |
512 KB |
31 - 40 |
1 MB |
41 - 50 |
2 MB |
51 - 60 |
4 MB |
61 - 70 |
8 MB |
71 - 80 |
16 MB |
81 - 90 |
32 MB |
91 - 100 |
64 MB |
Scenario 1
If the I/O group contains:
- At least one 8 GB node.
- At least one thin-provisioned or compressed volume in a data reduction
pool.
- A FlashCopy bitmap size for that I/O group set beyond 1.5 GB.
The command fails due to insufficient resources available.
Scenario 2
When a thin-provisioned or compressed volume is
created within a data reduction pool, the pool must have enough capacity
to create more volumes that track SCSI unmap operations from the host.
If this capacity is not available, the command fails.
Scenario 3
Volumes cannot be created in a data reduction pool
if offline thin-provisioned or compressed volumes exist in a data
reduction pool, either because of thin provisioning (out of space
or corruption), or a component underneath thin provisioning is holding
a volume in the pool offline.
An invocation
example
addvdiskcopy -mdiskgrp 0 -easytier off vdisk8
The resulting
output:
Vdisk [8] copy [1] successfully created
An invocation example for specifying storage
pools
addvdiskcopy -mdiskgrp 0 -vtype image -mdisk 13 -tier tier0_flash -easytier off vdisk9
The
resulting output:
Vdisk [9] copy [1] successfully created
An invocation example for configuring a mirror write algorithm
priority
addvdiskcopy -mdiskgrp 0 -mirrorwritepriority latency vdisk9
The
resulting output:
Vdisk [9] copy [1] successfully created
An invocation example for adding a compressed volume
copy
addvdiskcopy -mdiskgrp 1 -rsize 10% -compressed vdisk2
The
resulting output:
Vdisk [2] copy [1] successfully created
An invocation example for adding a compressed volume
copy
addvdiskcopy -mdiskgrp 0 -vtype image -mdisk 13 -tier tier_nearline vdisk9
The
resulting output:
Vdisk [9] copy [1] successfully created
An invocation example to add a deduplicated volume copy
addvdiskcopy -mdiskgrp datareductionpool10 -rsize 0 -autoexpand -deduplicated deduplicatedvolume6
The resulting output:
Vdisk [6] copy [1] successfully created