volcreate

Purpose

Creates an Oracle ADVM volume in the specified disk group.

Syntax and Description

volcreate -G diskgroup -s size
     [ --column number ] [ --width stripe_width ]
     [--redundancy {high|mirror|unprotected}]
     [--primary {hot|cold}] [--secondary {hot|cold}] volume

Table 15-2 describes the options for the volcreate command.

Table 15-2 Options for the volcreate command

Option Description

-G diskgroup

Name of the disk group containing the volume.

-s size

Size of the volume to be created in units of K, M, G, or T. The value must be a positive integer. The unit designation must be appended to the number specified. A space is not allowed between the number and the unit designation. For example: 200M or 20G

--column number

Number of columns in a stripe set. Values range from 1 to 8. The default value is 8.

--width stripe

Stripe width of a volume in units of K or M. The value can range from 4 KB to 1 MB, at power-of-two intervals. The default is 1M.

--redundancy {high|mirror|unprotected}

Redundancy of the Oracle ADVM volume which can be only specified for normal redundancy disk groups. If redundancy is not specified, the setting defaults to the redundancy level of the disk group and this is the recommended setting. The range of values is as follows: unprotected for non-mirrored redundancy, mirror for double-mirrored redundancy, or high for triple-mirrored redundancy.

--primary {hot|cold}

Intelligent Data Placement specification for primary extents, either hot or cold region.

--secondary {hot|cold}

Intelligent Data Placement specification for secondary extents, either hot or cold region.

volume

Name of the volume. Only alphanumeric characters are allowed; hyphens are not allowed. The first character must be alphabetic.

WARNING:

Specifying --redundancy unprotected means that Oracle ASM mirroring is not available for data recovery with the Oracle ADVM volume. The redundancy setting (normal) of the disk group does not provide mirroring for an unprotected Oracle ADVM volume. The unprotected configuration is not recommended for production environments as intermittent storage access failures can result in the loss of data. Backups are strongly recommended.

When creating an Oracle ADVM volume, a volume device name is created with a unique Oracle ADVM persistent disk group number that is concatenated to the end of the volume name. The unique number can be one to three digits.

On Linux, the volume device name is in the format volume_name-nnn, such as volume1-123. On Windows the volume device name is in the format asm-volume_name-nnn, such as asm-volume1-123. For information on mounting the volume device file, see "Creating an Oracle ACFS File System".

On Linux platforms, the volume name must be less than or equal to eleven alphanumeric characters, starting with an alphabetic character. On AIX platforms, the volume name must be less than or equal to twenty three alphanumeric characters, starting with an alphabetic character. On Windows and Solaris platforms, the volume name must be less than or equal to thirty alphanumeric characters, starting with an alphabetic character.

You can determine the volume device name with the volinfo command, described in "volinfo".

If the --column option is set to 1, then striping is disabled and the stripe width equals the volume extent size. The volume extent size is 8 MB if the disk group allocation unit (AU) is less than or equal to 8 MB. If the AU size is greater than 8 MB, then the Oracle ADVM volume extent size is equivalent to the disk group AU size. For information about Oracle ADVM limits, refer to "Limits of Oracle ADVM". Setting the --column option to 8 (the default) is recommended to achieve optimal performance with database data files and other files.

A successful volume creation automatically enables the volume device.

The volume device file functions as any other disk or logical volume to mount file systems or for applications to use directly.

When creating an accelerator volume, create the volume on a disk group with storage that is significantly faster than the primary volume's storage. For more information about the accelerator volume, refer to "mkfs".

For information about redundancy settings, see "Mirroring_ Redundancy_ and Failure Group Options". For information about hot and cold disk regions, see "Intelligent Data Placement".

Before creating an Oracle ADVM volume on AIX, ensure that the necessary user authorizations have been created. For information, refer to "Oracle ACFS Command-line Tools for the AIX Environment".

Examples

The following is an example of the volcreate command that creates volume1 in the data disk group with the size set to 10 gigabytes.

Example 15-1 Using the ASMCMD volcreate command

ASMCMD [+] >  volcreate -G data -s 10G --width 1M --column 8 volume1

ASMCMD [+] > volinfo -G data volume1
Diskgroup Name: DATA
 
         Volume Name: VOLUME1
         Volume Device: /dev/asm/volume1-123
         State: ENABLED
         Size (MB): 10240
         Resize Unit (MB): 64
         Redundancy: MIRROR
         Stripe Columns: 8
         Stripe Width (K): 1024
         Usage: 
         Mountpath: