2.3 – Define Logical Storage Design

What’s New in VMware® vSphere™ 4.1 — Storage
Storage I/O Control: It extends the familiar constructs of shares and limits, which have existed for CPU and memory, to address storage utilization through a dynamic allocation of I/O queue slots across a cluster of ESX servers.

SIOC provides a dynamic allocation mechanism that adjusts to changing conditions of a mixed workload. It leverages the I/O shares, which are set on the Virtual Machine Properties for each virtual disk, to distribute available I/O slots to ensure a quality of service is enforced not just at the host level, but across the collection of hosts that are sharing that datastore.

SIOC works only with block-based datastores and datastores that reside on a single extent and are managed by one vCenter management server

vStorage API for Array Integration
This API is currently supported by several storage partners and requires these partners to release a special version of their firmware to work with this API. In the vSphere 4.1 release, this array offload capability supports three primitives:
1. Full copy enables the storage arrays to make full copies of data within the array without having the ESX server read and write the data.
2. Block zeroing enables storage arrays to zero out a large number of blocks to speed up provisioning of virtual machines.
3. Hardware-assisted locking provides an alternative means to protect the metadata for VMFS cluster-file systems, thereby improving the scalability of large ESX server farms sharing a datastore.

Enabling vStorage API for Array Integration
By default these three primitives described above are not enabled upon install and must be enabled in the advanced settings for the ESX server, and they must have the correct array firmware loaded for this feature to work. Enabling or disabling these primitives is done through the advanced settings on the ESX servers.
Three settings under advanced settings:
DataMover.HardwareAcceleratedMove - full copy
DataMover.HardwareAcceleratedInit - block zeroing
VMFS3.HarwareAccelerated Locking - hardware-assisted locking

Support for 8Gb FC Host-Based Adaptors (HBAs)

Broadcom iSCSI offload functionality enables on-chip processing of the iSCSI protocol (as well as TCP and IP protocols), which frees up host CPU resources at 10GbE line rates over a single Ethernet port. This functionality provides extended performance benefits that meet the demands of bandwidth-intensive applications requiring high-performance block storage I/O for VMware ESX, servicing all instances of the virtual machine.