Creating a mirrored aggregate or traditional volume
Methods for creating a mirrored volume
You can create a mirrored aggregate or traditional volume using one of the following methods:
- Let Data ONTAP select the disks used to mirror the aggregate or traditional volume.
- Select the disks used to mirror the aggregate or traditional 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 aggregate or traditional volume by letting Data ONTAP select the disks used, complete the following step.
Step
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Action
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1
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Enter the following command:
{ aggr | vol } create { aggrname | volname} -m
ndisks[@disk-size]
aggrname is the name for the new aggregate. volname is the name for the new traditional volume (without the /vol/ prefix).
-m specifies a mirrored aggregate or traditional volume to Data ONTAP.
ndisks is the number of disks to use; 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 specifies the disk capacity, in gigabytes. There must be enough disks of this size available to both disk pools 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, the following command creates a mirrored aggregate that has two plexes, each plex containing three disks:
aggr create aggrA -m 6
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You select the disks
If you select the disks used to create a mirrored aggregate or traditional volume, you must ensure that you choose a correct number and size of disks from each pool.
To create a mirrored aggregate using disks you select, complete the following step.
Step
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Action
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1
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Enter the following command:
aggr create aggrname -m -d disk-list -d disk-list
aggrname is the name of the aggregate you are mirroring.
-m specifies a mirrored aggregate to Data ONTAP.
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, the following command creates a mirrored aggregate named aggrA with disks 6.1 and 6.2 on one plex and disks 8.1 and 8.2 on the other plex:
aggr create aggrA -m -d 6.1 6.2 -d 8.1 8.2
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To create a mirrored traditional volume using disks you select, complete the following step.
Step
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Action
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1
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Enter the following command:
vol create volname -m -d disk-list -d disk-list
volname is the name of the volume you are mirroring (without the /vol/ prefix).
-m specifies a mirrored volume to Data ONTAP.
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, the following command creates a mirrored volume named vol A with disks 6.1 and 6.2 on one plex and disks 8.1 and 8.2 on the other plex:
vol create volA -m -d 6.1 6.2 -d 8.1 8.2
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You select the disks with assistance from Data ONTAP
You can preview what disks Data ONTAP would select if it were to create a mirrored aggregate or traditional volume.
To create a mirrored aggregate by previewing the disks Data ONTAP would use in the form of a sample command, complete the following steps.
Step
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Action
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1
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Enter the following command:
aggr create aggrname -n -m ndisks[@disk-size]
aggrname is the name of the mirrored volume you are creating.
-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 aggregate to Data ONTAP.
ndisks is the number of disks to use. ndisks must be an even number.
disk-size specifies the disk capacity, in gigabytes. You must have enough available disks of the size you specify.
Result
Data ONTAP returns an aggr create command that specifies the disks.
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2
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If you want to...
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Then...
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Use the disks specified by Data ONTAP
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At the prompt, enter the aggr create command specified.
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Substitute other disks for one or more disks specified by Data ONTAP
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At the prompt, enter the aggr create command and substitute other disks for one or more of the disks specified.
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Example
In this example, the following command previews the command that Data ONTAP would use when creating a 4-disk mirrored aggregate called aggrB:
aggr create aggrB -n -m 4
Data ONTAP returns the following command:
aggr create aggrB -m -d 5.1 5.3 -d 8.3 8.4
To create a mirrored traditional volume by previewing the disks Data ONTAP would use in the form of a sample command, complete the following steps.
Step
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Action
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1
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Enter the following command:
vol create volname -n -m ndisks[@disk-size]
volname 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. ndisks must be an even number.
disk-size specifies the disk capacity, in gigabytes. You must have enough available disks of the size you specify.
Result
Data ONTAP returns a vol create command that specifies the disks.
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2
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If you want to...
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Then...
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Use the disks specified by Data ONTAP
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At the prompt, enter the vol create command specified.
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Substitute other disks for one or more disks specified by Data ONTAP
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At the prompt, enter the vol create command and substitute other disks for one or more of the disks specified.
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Example
In this example, the following command previews 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
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Part No. 210-01081_B0
File: syncmir5.htm
Last updated: 01-Dec-2005 16:36:26