Saturday, May 11, 2013

Create, expand, destroy aggregates on NetApp DataOnTap

Aggregates: OnTap combines one or more RaidGroups (any size) into a pool of disk space for creating multiple volumes.
Configuring an optimum RAID group size for an aggregate made up of disks requires a trade-off of factors. You must decide which factor—speed of recovery, assurance against data loss, or maximizing data storage space—is most important for the aggregate that you are configuring.

1. You cannot reduce the number of disks in an aggregate by removing data disks. The only way to reduce the number of data disks in an aggregate is to copy the data and transfer it to a new aggregate that has fewer data disks.
2. You are advised to keep your RAID groups homogeneous when possible. If needed, you can replace a mismatched disk with a more suitable disk later.
3. At a minimum, you should have at least one matching or appropriate hot spare available for each kind of disk installed in your storage system. However, having two available hot spares for all disks provides the best protection against disk failure.
Aggregate Creation:
aggr create aggr_name [-f] [-m] [-n] [-t {raid0 | raid4 | raid_dp}] [-r raidsize] [-T disk-type] -R rpm] [-L] [-B {32 | 64}] disk-list
Create an aggregate with all the avaialable disks on controller with described opions below. Also disable automatic snapshot and set snap reserve to '0' on the aggregate.
Aggregate Name: aggr0, Raid Type: raid_dp, Raid Size: 20, Disk Type: SAS, 64-bit
Step:1 Create aggregate
aggr create aggr0 -t raid_dp -r 20 -T SAS -B 64
If you want to specify disk list:
aggr create aggr0 -t raid_dp -r 20 -d 7a.1 7a.2 7a.3 7a.4.......7a.19
Step:2 Disable automatic aggregate Snapshot copy creation

aggr options aggr0 nosnap on
Step:3 Set the aggregate Snapshot reserve to 0 percent
snap reserve -A aggr0 0
Step:4 Verify
aggr status -r
Aggregate Expansion:
aggr add aggr_name [-f] [-n] [-g {raid_group_name | new | all}] disk_list
Add four 500-GB disks to the aggr0
Step:1 Add disks to aggregate
aggr add aggr0 4@500
aggr add aggr0 -g rg1 -d 7a.22 7a.23 7a.24 7a.25
Step:2 Verify
aggr status -r
After you add storage to an aggregate, run a full reallocation job on each FlexVol volume contained in that aggregate.

Destroy Aggregate:

I really really hope you are doing this action with full consciousness!

Step:1 Offline aggregate
Note: You use the aggr offline command to take an aggregate offline to perform maintenance on the aggregate, move it, or destroy it.

aggr offline aggr0

Step:2 Destroy aggregate
Note: Before you can destroy an aggregate, you must destroy all of the FlexVol volumes contained by that aggregate.

aggr destroy aggr0

Backout: Undestroy the aggregate

aggr undestroy aggr0
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