Hardware-based disk ownership

Disk ownership supported by storage system model

Storage systems that support only hardware-based disk ownership include NearStore, F800 series and the FAS250 storage systems. Storage systems that support only software-based disk ownership include the FAS270 and V-Series storage systems.

The FAS900 and FAS3000 series storage systems can be either a hardware- or a software-based system. If a storage system that has CompactFlash also has the SnapMover license enabled, it becomes a software-based disk ownership storage system.

The following table lists the type of disk ownership that is supported by NetApp storage systems.

Storage System	Hardware-based	Software-based
R100 series R200 series	X non-clustered only
FAS250	X non-clustered only
FAS270		X
V-Series		X
F87	X
F800 series	X
FAS900 series	X	X (with SnapMover license)
FAS3000 series	X	X (with SnapMover license)

How hardware-based disk ownership works

Hardware-based disk ownership is determined by two conditions: how a storage system is configured and how the disk shelves are attached to it.

Without Multipath I/O

If the storage system is not configured for Multipath I/O, the disk ownership is based on the following rules:

If clustering is not enabled, the single storage system owns all of the disks directly attached to it. This rule applies to direct-attached SCSI and NearStore ATA disks. For FC-AL disks, this rule applies to which port the disk shelf is attached to, which corresponds to the A loop or the B loop.
If clustering is enabled, the local storage system owns direct FC-AL attached disks connected to it on the A loop and its partner owns the disks connected to it on the B loop.
Note
Clustering is considered enabled if an InterConnect card is installed in the storage system, it has a partner-sysid environment variable, or it has the clustering license installed and enabled.
In either a single or clustered storage system with SAN switch-attached disks, a storage system with even switch port parity owns FCFLA attached disks whose A loop is attached to an even switch port or whose B loop is attached to an odd switch port.
In either a single or clustered storage system with SAN switch-attached disks, a storage system with odd switch port parity owns FCFLA attached disks whose A loop is attached to an odd switch port or whose B loop is attached to an even switch port.
In a clustered storage system with SAN disks attached with two switches, the above two rules apply to disks on both switches.
For information about V-Series systems, see the V-Series Software Setup, Installation and Administration Guide.

With Multipath I/O

If the storage system is configured for Multipath I/O, there are three methods supported that use hardware-based disk ownership rules (using Multipath without SyncMirror, with SyncMirror, and with four separate host adapters). For detailed information on how to configure storage system using Multipath I/O, see Multipath I/O for Fibre Channel disks.

Functions performed for all hardware-based systems

For all hardware-based disk ownership storage systems, Data ONTAP performs the following functions:

Recognizes all of the disks at bootup or when they are inserted into a disk shelf.
Initializes all disks as spare disks.
Automatically puts all disks into a pool until they are assigned to a RAID group.
The disks remain spare disks until they are used to create aggregates and are designated as data disks or as parity disks by you or by Data ONTAP.
Note
Some storage systems that use hardware-based disk ownership do not support cluster failover, for example, NearStore (the R100 and R200 series) systems.

How disks are assigned to pools when SyncMirror is enabled

All spare disks are in pool0 unless the SyncMirror software is enabled. If SyncMirror is enabled on a hardware-based disk ownership storage system, all spare disks are divided into two pools, Pool0 and Pool1. For hardware-based disk ownership storage systems, disks are automatically placed in pools based on their location in the disk shelves, as follows:

For all storage systems (except the FAS3000 series)
- Pool0 - Host adapters in PCI slots 1-7
- Pool1 - Host adapters in PCI slots 8-11
For FAS3000 series
- Pool0 - Onboard adapters 0a, 0b, and host adapters in PCI slots 1-2
- Pool1 - Onboard adapters 0c, 0d, and host adapters in PCI slots 3-4