Home > Articles

  • Print
  • + Share This
This chapter is from the book

Storage Array Type Plug-in (SATP)

Figure 5.2 depicts the relationship between SATP and NMP.

Figure 5.2

Figure 5.2. SATP

SATPs are PSA plug-ins specific to certain storage arrays or storage array families. Some are generic for certain array classes—for example, Active/Passive, Active/Active, or ALUA-capable arrays.

SATPs handle the following operations:

  • Monitor the hardware state of the physical paths to the storage array
  • Determine when a hardware component of a physical path has failed
  • Switch physical paths to the array when a path has failed

NMP communicates with SATPs for the following operations:

  • Set up a new logical device—claim a physical path
  • Update the hardware states of the physical paths (for example, Active, Standby, Dead)
  • Activate the standby physical paths of an active/passive array (when Active paths state is dead or unavailable)
  • Notify the plug-in that an I/O is about to be issued on a given path
  • Analyze the cause of an I/O failure on a given path (based on errors returned by the array)

Examples of SATPs are listed in Table 5.1:

Table 5.1. Examples of SATPs

SATP

Description

VMW_SATP_CX

Supports EMC CX that do not use the ALUA protocol

VMW_SATP_ALUA_CX

Supports EMC CX that use the ALUA protocol

VMW_SATP_SYMM

Supports EMC Symmetrix array family

VMW_SATP_INV

Supports EMC Invista array family

VMW_SATP_EVA

Supports HP EVA arrays

VMW_SATP_MSA

Supports HP MSA arrays

VMW_SATP_EQL

Supports Dell Equalogic arrays

VMW_SATP_SVC

Supports IBM SVC arrays

VMW_SATP_LSI

Supports LSI arrays and others OEMed from it (for example, DS4000 family)

VMW_SATP_ALUA

Supports non-specific arrays that support ALUA protocol

VMW_SATP_DEFAULT_AA

Supports non-specific active/active arrays

VMW_SATP_DEFAULT_AP

Supports non-specific active/passive arrays

VMW_SATP_LOCAL

Supports direct attached devices

How to List SATPs on an ESXi 5 Host

To obtain a list of SATPs on a given ESXi 5 host, you may run the following command directly on the host or remotely via an SSH session, a vMA appliance, or ESXCLI:

# esxcli storage nmp satp list

An example of the output is shown in Figure 5.3.

Figure 5.3

Figure 5.3. Listing SATPs

Notice that each SATP is listed in association with a specific PSP. The output shows the default configuration of a freshly installed ESXi 5 host. To modify these associations, refer to the “Modifying PSA Plug-in Configurations Using the UI” section later in this chapter.

If you installed third-party SATPs, they are listed along with the SATPs shown in Table 5.1.

  • + Share This
  • 🔖 Save To Your Account