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What are the rules for Advanced Disk Partitioning?

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Applies to

Answer

The following rules are enforced automatically when Advanced Disk Partitioning for versions 1 & 2 as specified.

  • ADPv1: 1 data partition (P1) and 1 root partition (P2)
  • ADPv2: 2 equally sized data partitions (P1, P2) and 1 root partition (P3)
  • ADPv1 is only supported for HDD and ADPv2 is only supported for SSD disks.
  • Root partitions can only be used for node root aggregates. 
  • A RAID group cannot have more than one partition from the same disk (ADPv2).
    • Example: 
      • For partitioned disk 0a.00.1, partitions 0a.00.1P1 and 0a.00.P2 can not be in the same RAID group. 
      • They can be in different RAID groups of the same aggregate.
  • Partitioned and non-partitioned disks can be present together in the same aggregate, however, they must be in different RAID groups.
  • The only supported RAID types for aggregates containing root-data partitioned disks (ADPv1) are RAID-TEC and RAID-DP.  RAID4 is not supported.
  • The supported RAID types for aggregates containing root-data-data partitioned disk (ADPv2) are RAID-TEC, RAID-DP, and RAID4 (ONTAP 9.5 and later).
  • All-Flash FAS (AFF) systems only support ADPv2.
  • For ADPv1, the spares requirements are as shown:
    • There must be (1) whole HDD available on each node of the HA pair.  The disk can be partitioned, but both partitions must be available as spares. 
    • If there is a mix of partitioned disk and non-partitioned disk RAID groups, then the requirement are (2) whole spares for each node that has both a partitioned disk RAID group and a non-partitioned RAID group.
  • In default for ADPv1, the owner of partitions are same as the container; for ADPv2, the owner of the secondary data partition should be different with the root partition and primary data partition.
  • For AFF systems using ADPv2 require spares as shown
    • If all RAID groups are partitioned disks, with the same disk container type; (1) a whole spare per HA is required.  The spare can be partitioned across the nodes.
    • If there is a mix of partitioned disk and non-partitioned disk RAID groups, then the requirement is (1) a whole spare per node so that a spare is always available both for the partitioned disk RAID groups and the whole disk RAID groups.
  • ADPv1 initializes an HA pair with up to 24 HDD partitions; however, more partitions can be created after initialization
  • ADPv2 initializes an HA pair with up to 48 SSD partitions; however, more partitions can be created after initialization
  • For ADPv2, the minimum recommended same size or type to satisfy the hot spares/node requirements within ONTAP with mixed whole and partitioned RAID groups:
Disk Count Number of Spares Required per Node
1 - 100 1
101 - 400 2
401 - 600 3
601+ 4

Additional Information

  • The following example error message is reported when attempting to change the RAID type to an unsupported version:

cluster1::> aggr modify -aggregate aggr0 -raidtype raid4

Error: command failed: Failed to modify raidtype of aggregate "aggr0".
Reason: Change to raidtype RAID4 is not supported. Fields that were successfully modified: none

  • NetApp Hardware Universe contains extensive information for each supported platform on initial partition sizes for each supported disk type.
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