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Configuring RAID type and group size while creating a volume

About RAID group type  Top

When you use the vol create command to create a volume, the volume's RAID type and group size can be set by default Data ONTAP values, or you can directly specify the size and type of a volume's RAID groups through the vol create command options.

Specifying the RAID type at volume creation  Top

To specify the size and type of a volume's RAID groups when you create that volume, complete the following steps.

Step

Action

1

To view the filer disks that are "spare" and thus available to include in a new volume. Enter the following command:

vol status -s

Result

The device number, shelf number, and capacity of all spare disks on the filer are listed. The filer should contain spare disks of sufficient number and capacity to

  • Support the volume that you want to create
  • Provide enough spare disks to serve as replacement disks should disk failure occur in any filer volume.

    To fully support a volume's RAID disk failure protection, at least one spare disk is required for that volume.

    The size of the spare disks should be equal to or greater than the size of the volume disks that the spare disks might replace.

    Network Appliance recommends that spare disks include disks to match the size of any of the volume disks that might require replacement.

2

To specify RAID group size and RAID group type, use the vol create command's -r and -t options when you create the volume. Enter

vol create volname [-m] [-t {raid_4|raid_dp}] 
[-r raid_group_size] disk_list

volname is the name of the volume you want to create.

-m specifies the optional creation of a SyncMirror-replicated volume if you want to supplement RAID protection with SyncMirror protection. A SyncMirror license is required for this feature.

-t {raid_4|raid_dp} specifies the type of RAID protection (RAID 4 or RAID DP) that you want to provide for this volume. If no RAID type is specified, the default value (raid_dp on NearStore appliances, raid_4 on all others) is applied.

-r raid-group-size is the number of drives per RAID group that you want for this volume. If no RAID group size is specified, the default value for your appliance model is applied. For a listing of default and maximum RAID group sizes, see Maximum and default RAID group sizes.

disk_list specifies the disks to include in the volume that you want to create. It can be expressed in the following formats:

  • ndisks[@disk-size]

    ndisks is the number of disks to use. It must be at least 2.

    disk-size is the disk size to use, in gigabytes. You must have at least ndisk available disks of the size you specify.

  • -d disk_name1 disk_name2... disk_nameN

    disk_name1, disk_name2, and disk_nameN are disk IDs of one or more available disks; use a space to separate multiple disks.

Example

The following command creates the volume newvol with RAID DP protection. RAID group size is 16 disks. Since the volume consists of 32 disks, those disks will form 2 RAID groups, rg0 and rg1:

vol create newvol -t raid_dp -r 16 32@36
3

To verify the RAID structure of the volume that you just created, enter the following command:

vol status volname -r

Result

The parity and data disks for each RAID group in the volume just created are listed. In volumes with RAID 4 protection, you will see "parity," and "data" disks listed for each RAID group in a volume. In volumes with RAID DP protection you will see "parity," "dParity," and "data" disks listed for each RAID group

4

To verify that spare disks of sufficient number and size exist on the filer to serve as replacement disks in event of disk failure in one of the RAID groups in the volume that you just created, enter the following command:

vol status -s

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