You can add disks or array LUNs to an aggregate so that it can provide more storage to its associated volumes. If you need to add enough storage to a 32-bit aggregate to increase its size beyond 16 TB, you can do so; this operation expands the aggregate to 64-bit format.
Before you begin
- You must understand the requirement to add disks or array LUNs owned by the same system
- For aggregates composed of disks, you must understand the following:
- Benefits of keeping your RAID groups homogeneous for disk size and speed
- Which types of disks can be used together
- Checksum rules when disks of more than one checksum type are in use
- How to ensure that the correct disks are added to the aggregate (the disk addition operation cannot be undone)
- How to add disks to aggregates from heterogeneous storage
- Minimum number of disks to add for best performance
- Number of hot spares you need to provide for protection against disk failures
- Requirements for adding disks from multi-disk carrier disk shelves
- If you are adding cache to a Flash Pool aggregate, the cache limit for your platform model and how much cache you are adding towards the limit
About this task
Following these best practices when you add storage to an aggregate optimizes aggregate performance:
- Add a complete RAID group at a time.
The new RAID group does not have to be exactly the same size as the existing RAID groups, but it should not be less than one half the size of the existing RAID groups.
- If any small RAID groups exist already, you can bring them up to the size of the other RAID groups, as long as you add at least as many data drives as are already in the RAID group.
- Avoid adding a small number of drives to an existing RAID group.
Doing so results in the added disks being the target for a disproportionate percentage of new data, causing the new disks to become a performance bottleneck.
For information about adding SSDs to a Flash Pool aggregate, see Technical Report 4070: NetApp Flash Pool Design and Implementation Guide.
- Verify that appropriate spare disks or array LUNs are available for you to add: storage disk show -spare -owner node_name
For disks, make sure that enough of the spares listed are of the correct type, size, speed, and checksum type for the target RAID group in the aggregate to which you are adding the disks.
- Add the disks or array LUNs: storage aggregate add-disks -aggregate aggr_name [-raidgroup raid_group_name] disks
If you are adding disks with a different checksum than the aggregate, as when creating a Flash Pool aggregate, or if you are adding disks to a mixed checksum aggregate, you must either specify the disks to be added with a disk list or use the -checksumstyle parameter.
If you are adding disks to a Flash Pool aggregate, you must either specify the disks to be added with a disk list or use the -disktype parameter to specify the disk type.
If you specify the -raidgroup parameter, the storage is added to the RAID group you specify. raid_group_name is the name that Data ONTAP gave to the group—for example, rg0. If you are adding SSDs to the SSD cache of a Flash Pool aggregate, you do not need to specify the RAID group name; the SSD RAID group is selected by default based on the type of the disks you are adding.
disks specifies the disks to be added in one of the following ways:
- -diskcount, usually further qualified by disk type or checksum type
- -disklist disk1 [disk2...]
If you are adding disks to a mirrored aggregate and you are specifying disk names, you must also use the -mirror-disklist parameter.
- If the previous step was unsuccessful because you are adding disks to a 32-bit aggregate and the additional disks would cause its size to exceed 16 TB, complete the following steps to expand the aggregate to 64-bit:
- Repeat the storage aggregate add-disks command you entered before, with the -64bit-upgrade normal parameter added.
For example, if you entered the storage aggregate add-disks -diskcount 10 -disktype SAS command, you would enter the following command: storage aggregate add-disks -diskcount 10 -disktype SAS -64bit-upgrade normal
Data ONTAP checks each volume associated with the aggregate to ensure that it has enough free space to be expanded to 64-bit. If all of the volumes have enough free space, the disks are added and the aggregate is expanded to the 64-bit format. If any of the volumes are too full to be expanded, the command fails.
- If the previous command failed, run the command again, replacing the -64-bit-upgrade normal parameter with the -64-bit-upgrade check parameter and following the instructions in the output of that command.
- If you had to add more space to any volume, repeat the storage aggregate -add-disks command again, this time with the -64bit-upgrade normal parameter.
- If you want to ensure that the disk usage quota accounting for this aggregate is exactly correct, reinitialize quotas on all of its volumes.
If you do not reinitialize quotas, quotas on volumes associated with this aggregate will remain active, but the disk usage accounting will be slightly lower than the actual usage until the next time quotas are reinitialized.