In-the-Lab: Full ESX/vMotion Test Lab in a Box, Part 2

In Part 1 of this series we introduced the basic Lab-in-a-Box platform and outlined how it would be used to provide the three major components of a vMotion lab: (1) shared storage, (2) high speed network and (3) multiple ESX hosts. If you have followed along in your lab, you should now have an operating VMware ESXi 4 system with at least two drives and a properly configured network stack.

In Part 2 of this series we're going to deploy a Virtual Storage Appliance (VSA) based on an open storage platform which uses Sun's Zetabyte File System (ZFS) as its underpinnings. We've been working with Nexenta's NexentaStor SAN operating system for some time now and will use it - with its web-based volume management - instead of deploying OpenSolaris and creating storage manually.

Part 2, Choosing a Virtual Storage Architecture

To get started on the VSA, we want to identify some key features and concepts that caused us to choose NexentaStor over a myriad of other options. These are:

• NexentaStor is based on open storage concepts and licensing;


• NexentaStor comes in a "free" developer's version with 4TB 2TB of managed storage;


• NexentaStor developer's version includes snapshots, replication, CIFS, NFS and performance monitoring facilities;


• NexentaStor is available in a fully supported, commercially licensed variant with very affordable $/TB licensing costs;


• NexentaStor has proven extremely reliable and forgiving in the lab and in the field;


• Nexenta is a VMware Technology Alliance Partner with VMware-specific plug-ins (commercial product) that facilitate the production use of NexentaStor with little administrative input;


• Sun's ZFS (and hence NexentaStor) was designed for commodity hardware and makes good use of additional RAM for cache as well as SSD's for read and write caching;


• Sun's ZFS is designed to maximize end-to-end data integrity - a key point when ALL system components live in the storage domain (i.e. virtualized);


• Sun's ZFS employs several "simple but advanced" architectural concepts that maximize performance capabilities on commodity hardware: increasing IOPs and reducing latency;

While the performance features of NexentaStor/ZFS are well outside the capabilities of an inexpensive "all-in-one-box" lab, the concepts behind them are important enough to touch on briefly. Once understood, the concepts behind ZFS make it a compelling architecture to use with virtualized workloads. Eric Sproul has a short slide deck on ZFS that's worth reviewing.

ZFS and Cache - DRAM, Disks and SSD's

Legacy SAN architectures are typically split into two elements: cache and disks. While not always monolithic, the cache in legacy storage typically are single-purpose pools set aside to hold frequently accessed blocks of storage - allowing this information to be read/written from/to RAM instead of disk. Such caches are generally very expensive to expand (when possible) and may only accomodate one specific cache function (i.e. read or write, not both). Storage vendors employ many strategies to "predict" what information should stay in cache and how to manage it to effectively improve overall storage throughput.

[caption id="attachment_968" align="aligncenter" width="405" caption="New cache model used by ZFS allows main memory and fast SSDs to be used as read cache and write cache, reducing the need for large DRAM cache facilities."][/caption]

In-the-Lab: Full ESX/vMotion Test Lab in a Box, Part 1

There are many features in vSphere worth exploring but to do so requires committing time, effort, testing, training and hardware resources. In this feature, we'll investigate a way - using your existing VMware facilities - to reduce the time, effort and hardware needed to test and train-up on vSphere's ESXi, ESX and vCenter components. We'll start with a single hardware server running VMware ESXi free as the "lab mule" and install everything we need on top of that system.

Part 1, Getting Started

To get started, here are the major hardware and software items you will need to follow along:

Recommended Lab Hardware Components

• One 2P, 6-core AMD "Istanbul" Opteron system


• Two 500-1,500GB Hard Drives


• 24GB DDR2/800 Memory


• Four 1Gbps Ethernet Ports (4x1, 2x2 or 1x4)


• One 4GB SanDisk "Cruiser" USB Flash Drive


• Either of the following:
  
  
  
  • One CD-ROM with VMware-VMvisor-Installer-4.0.0-164009.x86_64.iso burned to it
  
  
  • An IP/KVM management card to export ISO images to the lab system from the network
  
  
  
  

Recommended Lab Software Components

• One ISO image of NexentaStor 2.x (for the Virtual Storage Appliance, VSA, component)


• One ISO image of ESX 4.0


• One ISO image of ESXi 4.0


• One ISO image of VCenter Server 4


• One ISO image of Windows Server 2003 STD (for vCenter installation and testing)

For the hardware items to work, you'll need to check your system components against the VMware HCL and community supported hardware lists. For best results, always disable (in BIOS) or physically remove all unsupported or unused hardware- this includes communication ports, USB, software RAID, etc. Doing so will reduce potential hardware conflicts from unsupported devices.

The Lab Setup

We're first going to install VMware ESXi 4.0 on the "test mule" and configure the local storage for maximum use. Next, we'll create three (3) machines two create our "virtual testing lab" - deploying ESX, ESXi and NexentaStor running directly on top of our ESXi "test mule." All subsequent tests VMs will be running in either of the virtualized ESX platforms from shared storage provided by the NexentaStor VSA.

[caption id="attachment_929" align="aligncenter" width="450" caption="ESX, ESXi and VSA running atop ESXi"][/caption]

Next up, quick-and-easy install of ESXi to USB Flash...