Creating mirrored volumes

Creating a mirrored volume when creating a volume

Methods for creating a mirrored volume

You can create a mirrored volume when creating a volume using one of the following methods:

Let Data ONTAP select the disks used to mirror the volume.
Select the disks used to mirror the volume yourself.
Preview the disks Data ONTAP would use, then either use those disks or replace one or more of the disks with disks you choose.

Data ONTAP selects the disks

To create a mirrored volume by letting Data ONTAP select the disks used, complete the following step.

Step	Action
1	At the prompt, enter the following command: *vol create vol-name* -m ndisks[@disk-size]** vol-name is the name for the new volume (without the /vol/ prefix). `-m` specifies a mirrored volume to Data ONTAP. ndisks is the number of disks to use; ndisks must be at least 4 and an even number. Even numbers are required because half of the disks specified by ndisks go to one plex from one disk pool and half go to the other plex from another disk pool. disk-size is a number that specifies the disk size to use, in gigabytes. You must have half of the ndisks available disks of the size you specify in one disk pool and half of the ndisks available disks of the size you specify in another disk pool if you use this option. Note If you use the `disk-size` option, first determine the size of spare disks in the disk pools using the `vol` `status` `-r` command. Example: In this example, use the following command to create a mirrored volume that has two plexes, each plex containing three disks: vol create volA -m 6

Step

Action

At the prompt, enter the following command:

vol create vol-name -m ndisks[@disk-size]

vol-name is the name for the new volume (without the /vol/ prefix).

-m specifies a mirrored volume to Data ONTAP.

ndisks is the number of disks to use; ndisks must be at least 4 and an even number. Even numbers are required because half of the disks specified by ndisks go to one plex from one disk pool and half go to the other plex from another disk pool.

disk-size is a number that specifies the disk size to use, in gigabytes. You must have half of the ndisks available disks of the size you specify in one disk pool and half of the ndisks available disks of the size you specify in another disk pool if you use this option.

Note
If you use the disk-size option, first determine the size of spare disks in the disk pools using the vol status -r command.

Example:

In this example, use the following command to create a mirrored volume that has two plexes, each plex containing three disks:

vol create volA -m 6

You select the disks

If you select the disks used to create a mirrored volume, you must ensure that you use the correct number of disks, the correct size of disks, and that the disks for each volume plex come from different pools.

To create a mirrored volume using disks you select, complete the following step.

Step	Action
1	At the prompt, enter the following command: vol create vol-name -m -d disk-list -d disk-list `-m` specifies a mirrored volume to Data ONTAP. vol-name is the name of the volume you are mirroring (without the /vol/ prefix). disk-list consists of the disk IDs of two or more available disks; separate multiple disks with a space. Both `-d` options must be used, one for each plex. Note Specifying only one disk set using the `-d` option will fail. Example In this example, use the following command to create a mirrored volume named vol A with disks 6.1 and 6.2 on one plex and with disks 8.1 and 8.2 on the other plex: vol create volA -m -d 6.1 6.2 -d 8.1 8.2

Step

Action

At the prompt, enter the following command:

vol create vol-name -m -d disk-list -d disk-list

-m specifies a mirrored volume to Data ONTAP.

vol-name is the name of the volume you are mirroring (without the /vol/ prefix).

disk-list consists of the disk IDs of two or more available disks; separate multiple disks with a space. Both -d options must be used, one for each plex.

Note
Specifying only one disk set using the -d option will fail.

Example

In this example, use the following command to create a mirrored volume named vol A with disks 6.1 and 6.2 on one plex and with disks 8.1 and 8.2 on the other plex:

vol create volA -m -d 6.1 6.2 -d 8.1 8.2

You select the disks with assistance from Data ONTAP

Data ONTAP has a preview option that you can use to view what disks Data ONTAP would select if it were to create a mirrored volume.

To create a mirrored volume by previewing disks Data ONTAP would use in the form of a sample command, complete the following steps.

Step	Action
1	At the prompt, enter the following command: *vol create vol-name* -n -m ndisks[@disk-size]** vol-name is the name of the mirrored volume you are creating (without the /vol/ prefix). `-n` specifies to Data ONTAP not to create the mirrored volume, but to show the disks that it would use if it did create the mirrored volume. `-m` specifies a mirrored volume to Data ONTAP. ndisks is the number of disks to use. Creating a mirrored volume will fail if the number of disks is an odd number. disk-size is a number that specifies the disk size to use, in gigabytes. You must have at least ndisks available disks of the size you specify. Result Data ONTAP returns a `vol` `create` command that specifies the disks.
2	If you want to...	Then...
	Use the disks specified by Data ONTAP	At the prompt, enter the `vol` `create` command specified.
	Substitute other disks for one or more disks specified by Data ONTAP	At the prompt, enter the `vol create` command and substitute other disks for one or more of the disks specified.

Example

In this example, use the following command to preview the command that Data ONTAP would use when creating a 4-disk, mirrored volume called volB:

vol create volB -n -m 4

Data ONTAP returns the following command:

vol create volB -m -d 5.1 5.3 -d 8.3 8.4

Creating mirrored volumes

Creating a mirrored volume when creating a volume

Methods for creating a mirrored volume

Data ONTAP selects the disks

Example:

You select the disks

Example

You select the disks with assistance from Data ONTAP

Result

Example