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Utilizing VMWare With Your Storage Infrastructure

VMWare is a powerful software tool that can empower your IT staff to build a much more flexible and resilient environment for business applications. There are several benefits to utilizing VMWare with your SAN, NAS or iSCSI storage infrastructure.

 

    • Availability – Shared data storage systems on redundant LAN or SAN Fibre Channel fabrics provide the ability for users to use tools such as VMWare VMotion and Site Recovery Manager to move, recover and monitor VMs with limited to zero system downtime

 

    • Redundancy – Extend multi-pathing to all virtual machines, as well as extend failure resistance

 

    • Performance – Makes load balancing and high availability more affordable by eliminating dedicated standby hardware

 

  • Disaster Recovery – Disaster Recovery capabilities are enhanced when bare metal restore limitations are removed due to the VMWare hypervisor

While there are multiple benefits of shared storage for VMWare, you need to determine when your storage is configured correctly.

 

Properly planning the necessary storage capacity for an optimized VMWare environment requires proper planning and continuous performance tuning. The ultimate goal of performance optimization is finding and eliminating all possible roadblocks that reduce the full utilization of the Core Four resources (CPU, Network, Memory, and Storage). Here, we will discuss eliminating roadblocks for storage.

Storage Selection

When determining the best place in your storage infrastructure to deploy your VMWare environment, selecting the proper storage array or configuration is one of the most important factors. There is always the obvious trade-off between cost and performance and storage should divided into tiers depending on a number of factors. In the end, every application should be supported on the tier best suited for the business with a balance of cost in mind.

Tier 1 – Offers maximum performance and availability. This tier may utilize built-in snapshots to facilitate point-in-time restorations and supports replication, full storage  processor redundancy, and Fibre Channel, SAS or SSD drive technology. Smaller, faster disk will improve performance here. This is a higher cost per spindle tier.

Tier 2 – Offers mid-range performance, less availability than high-tier storage, limited storage processor redundancy, and perhaps slower, larger Fibre Channel drives.

Tier 3 – Offers limited performance and little storage redundancy. This tier should be built on high capacity, lower performance SATA drives.

NOTE: Not all VMWare applications or environments need to be in Tier 1., if certain elements call for Tier 2 or Tier 3 storage (such as redundancy or snapshots) there may be 收納師 alternative methods for delivery, which include but are not limited to:

 

  • Repurposing / Retrofitting a legacy storage platform
  • Utilizing 10K 146 or 300GB fibre channel drives in leui of SATA drives
  • Swapping SATA for fibre channel drives
  • De-installed brand named storage arrays and storage expansion upgrades

Disk Drives: Fibre vs. Sata vs. SSD vs. SAS

 

Assessing the correct tier for various applications is a critical step that cannot be skipped. When determining which application to run on high-performance disks and which ones to save for SATA-based tiers, it may help to ask yourself a few questions first.

 

  • How critical is the VMWare environment to your business?
  • What are the application-specific performance and availability requirements?
  • What are the applications’ point-in-time (PiT) restoration requirements?
  • What kind of backup requirements does this application have?
  • Do I need to replicate this application’s data?

Many storage managers often find themselves deploying SATA technology for VMWare infrastructure, only to find themselves resource constrained with 6 months. When considering the type of disk drive to deploy, consider the long term requirements for the environment.

 

Properly Configuring the Storage Array

Storage array design will require storage managers to map the defined storage requirements to the resources of the storage array using these guidelines:

 

    • Each RAID group provides a specific tiers of I/O performance, redundancy, and capacity. LUNs assigned to particular RAID groups should be based on these requirements. For example, high performance applications may be assigned to LUNS with RAID 10 configurations to increase I/O and spindle count

 

    • Don’t skimp: If a particular RAID group is unable to ensure the required I/O performance, capacity, and proper response times, you must define an additional RAID group for the next set of LUNs. It is imperative that you supply sufficient RAID-group resources for each set of LUNs.

 

  • The storage arrays must distribute the RAID groups across all back-end and internal channels and access paths. This ensures load balancing of all I/O requests to meet specific performance requirements of I/O operations per second and response times.

Peak Period Activity

 

It is important to base the design of the SAN around peak-period active and consider the nature of the I/O within those peak periods of time. You may find that additional storage resources and capacity are required to handle sudden spikes.

For example, a peak period may occur during batch processing or during morning usage spikes when end-users are coming online. This might be characterized by several peaking I/O sessions requiring twice to three times the average for the entire peak period. Without additional storage resources to handle peak activity, I/O demands will exceed the capacity of a storage array and may result in delayed response times.

Special Requirements for High Availability

Production systems need to be designed to eliminate all single points of failure. Make sure that redundancy is built into the storage design at all levels of the virtualized platform. Make sure that you build in additional switches, HBAs and HBA channels, and storage processors that create effective and redundant access paths to your data.

This can be done in a number of ways:

 

  • Redundant Storage Components – Redundant SAN hardware such as HBAS, switches and directors and access ports are necessary for full redundancy. In certain cases, a redundant storage array may be part of the design