- Native Multipathing
- Storage Array Type Plug-in (SATP)
- Path Selection Plugin (PSP)
- Third-Party Plug-ins
- Multipathing Plugins (MPPs)
- Anatomy of PSA Components
- I/O Flow Through PSA and NMP
- Listing Multipath Details
- Claim Rules
- MP Claim Rules
- Plug-in Registration
- SATP Claim Rules
- Modifying PSA Plug-in Configurations Using the UI
- Modifying PSA Plug-ins Using the CLI
Each storage device is managed by one of the PSA plug-ins at any given time. In other words, a device cannot be managed by more than one PSA plug-in.
For example, a host that has a third-party MPP installed alongside with NMP, devices managed by the third-party MPP cannot be managed by NMP unless the configuration is changed to assign these devices to NMP. The process of associating certain devices with certain PSA plug-ins is referred to as claiming and is defined by Claim Rules. These rules define the correlation between a device and NMP or MPP. NMP has additional association between the claimed device and a specific SATP and PSP.
This section shows you how to list the various claim rules. The next section discusses how to change these rules.
Claim rules can be defined based on one or a combination of the following:
- Vendor String—In response to the standard inquiry command, the arrays return the standard inquiry response, which includes the Vendor string. This can be used in the definition of a claim rule based on the exact match. A partial match or a string with padded spaces does not work.
- Model String—Similar to the Vendor string, the Model string is returned as part of the standard inquiry response. Similar to the Vendor string, a claim rule can be defined using the exact match of the Model string and padded spaces are not supported here.
- Transport—Defining a claim rule based on the transport type, Transport facilitates claiming of all devices that use that transport. Valid transport types are block, fc, iscsi, iscsivendor, ide, sas, sata, usb, parallel, and unknown.
- Driver—Specifying a driver name as one of the criteria for a claim rule definition allows all devices accessible via such a driver to be claimed. An example of that is a claim rule to mask all paths to devices attached to an HBA that uses mptscsi driver.