- 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
- Summary
This chapter is from the book
This chapter is from the book
This chapter is from the book
Storage Array Type Plug-in (SATP)
Figure 5.2 depicts the relationship between SATP and NMP.
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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.
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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.