Intro to Storage I/O Control

SIOC was covered in a previous blog post. Details can be found here – http://blogs.vmware.com/vsphere/2011/09/storage-io-control-enhancements.html. In a nutshell, if SIOC detects that a pre-defined latency threshold for a particular datastore has been exceeded, it will throttle the amount of I/O a VM can queue to that datastore based on a ‘shares’ mechanism. When the contention is alleviated, SIOC will stop and VMs can then begin to use the datastore without any throttling. This avoids the ‘noisy neighbor’ problems when one VM can hog all the bandwidth to a shared datastore. The point to note here is that SIOC is working on a per VM basis, and deals with datastore objects.

SIOC was first introduced in vSphere 4.1, but only for block storage devices (FC, iSCSI, FCoE) only. In vSphere 5.0, we introduced SIOC support for NFS datastores.

Intro to Network I/O Control (NIOC)

There is a nice overview of NIOC on the networking blog here – http://blogs.vmware.com/networking/2010/07/got-network-io-control.html. Again, in a nutshell, NetIOC allows you to define a guaranteed bandwidth for different vSphere network traffic types.

NIOC uses a software approach to partitioning physical network bandwidth among the different types of network traffic flows. For example, you can guarantee a minimum NFS bandwidth/latency when a vMotion operation is initiated on the same network & prevent the vMotion operation from having an impact on the NFS traffic flow. The point to note here is that NIOC is working on a network traffic stream, e.g. NFS, and deals with NIC ports.

Go hereto read all about how these technologies compliment eachother.

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The development of TCP offload engines marks a significant advance for all TCP/IP based protocols, including iSCSI. Although TCP provides session integrity in potentially congested or unstable networks, it incurs significant processing overhead on the host CPU. Offloading this processing to a host Ethernet adapter frees host CPU cycles and enables much higher performance solutions.

Because block I/O transactions can generate sustained high volumes of TCP/IP exchanges, IP storage is a direct beneficiary of TOE technology. With the burden of TCP overhead removed from the host CPU, only iSCSI processing is required. The remaining challenge for CPU utilization is optimizing iSCSI handling so blocks of data can be served to the host more efficiently. With clever engineering, wire-speed performance can be achieved when running software iSCSI on an optimized TOE-accelerated network adapter.

Remember that not all network adapters support TOE nativly via ESXi, so check the Hardware Compatability List and make sure your adapter is fully supported. Read the full PDF here. Page 6 is where it starts to explain the benefits of TOE and iSCSI.

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To give organizations affordable, easy-to-deploy infrastructure virtualization, HP and VMware have combined VMware vSphere™ Essentials Plus with the HP P4000 Virtual SAN Appliance (VSA). The HP P4000 is the only software SAN certified as VMware Ready™. The new integrated product complements “always-on” IT from VMware for small and medium businesses (SMBs) with highly available storage from HP. It provides backup and recovery with shared storage capabilities to help SMBs start on the path to cloud-based IT services.

Check out the overview and features of the HP Storagework P4000. Also check out this link that goes over their Desktop and Connectivity features.