User guide

Technical white paper | HP Enterprise Virtual Array Storage and VMware vSphere 4.x and 5.x configuration best practices
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VMware vStorage API for Array Integration (VAAI)
Starting with firmware 10100000, the HP EVA Storage arrays began supporting VMware VAAI. VMware VAAI provides
storage vendors access to a specific set of VMware Storage APIs, which enable offloading specific I/O and VM management
operations to the storage array. With hardware offload, an administrator is able to reduce memory and CPU consumption on
VAAI enabled ESX/ESXi hosts, reduce storage array port and fabric I/O traffic, and significantly increase performance and
scalability of the configuration. Please consult HP support pages for the latest active and supported EVA firmware versions
that support VAAI.
VMware VAAI storage integration is made possible by leveraging specific primitives within the API. Each of the primitives
enables hardware offload of a specific capability. The following table summarizes the VAAI primitives support by HP EVA
Storage
Table 8. VAAI Primitives support
Primitive
Equivalent Name
ESX 4.1/ESXi 4.1
ESXi 5.x
Full Copy/Hardware Assisted Move
XCOPY
YES
YES
Block Zeroing/Hardware Assisted Zeroing
WRITE SAME
YES
YES
Hardware Assisted Locking
ATS
YES
YES
Out of Space Awareness
TP Stun (VM Pause)
YES
YES
Thin Provisioning
Thin Provisioning Reporting
TP CAPABILITY
NA
YES
Soft Threshold Monitoring
NA
NA
YES
Hard Threshold Monitoring
NA
NA
YES
Space Reclamation
UNMAP
NA
YES*
ESX VAAI Software Plugin required
NA
YES
NO
* UNMAP supported in XCS 1120000 or newer. See space reclamation section below.
Table 8 summarizes VAAI primitives supported with HP EVA Storage for ESX/ESXi 4.1 and ESXi 5. A few important things to
note from this summary are:
• VAAI Support
VMware only supports VAAI on ESXi/ESX 4.1 and ESXi 5. ESX/ESXi 4.0 is not supported. Customers using vSphere 4 will
need to upgrade to vSphere 4.1 at minimum to benefit from VAAI offload acceleration. It is recommended to upgrade to
ESXi 5.x in order to leverage a much simpler VAAI configuration, because ESXi 5 does not require a VAAI software plugin.
• VAAI Software Plugin
Each storage vendor provides a VAAI software plugin for their respective arrays. A VAAI plugin is required when using
ESX/ESXi 4.1. Some arrays have this software plugin built into ESX and require no asynchronous installation. The HP EVA
Storage VAAI plugin is a software plugin that must be asynchronously downloaded and installed on ESX/ESXi 4.1. Note
that for HP EVA Storage arrays, a VAAI software plugin is not required for ESXi 5.x.
• Thin Provisioning
Thin Provisioning support was introduced with ESXi 5 and is not supported on ESX/ESXi 4.1
• TP STUN (VM Pause)
Despite ESX/ESXi 4.1 not supporting any of the Thin Provisioning features, ESX/ESXi 4.1 does support the ability to pause
a VM, on detection of an out of space condition.