Optimizing your Virtual Machines Performance

E-Guide

Optimizing your Virtual Machines

Performance

Storage virtualization can lower costs and increase capacity on physical servers by sharing them among several virtual machines. However, there are a number of best practices to consider when using or thinking about server virtualization. This guide will go in depth about the strengths and weaknesses of data deduplication products and data reduction technologies.

E-Guide

Optimizing your Virtual Machines

Performance

Table of Contents

Evaluating data deduplication products for SMBs

Best practices for using server virtualization in your storage environment About EMC

Find an EMC Partner near you!

About Content Archiving Solutions About ESTI

About M&S Technologies About Pride Technologies About Solutions II

About Steelhead Data

Evaluating data deduplication products for SMBs

By: Marc Staimer

In my previous article, I identified the different types of data reduction and data

deduplication technologies, including hardware or software compression, file deduplication, block/variable block deduplication, delta-block optimization, and application-aware

deduplication. I also discussed how data reduction and dedupe can be implemented as inline and post-processing in backup software, network-attached storage (NAS) appliances or virtual tape libraries (VTLs). This tip will examine the strengths and weaknesses of data deduplication products and data reduction technologies.

Hardware compression or software compression

Compression is a good choice for data that is uncompressed and unencrypted. It is also useful for extending the life of older storage systems. Hardware compression tends to be faster than software compression, with measurably lower latency per transaction. However, software compression such as LZO compression, can be downloaded at no cost.

Both types of compression are not very good at reducing duplicate data. If the files have been stored multiple times, no matter how good the compression algorithm is, there will be multiple copies of the compressed files.

In addition, compression is also not a very effective choice when the data or files are encrypted or compressed (such as Microsoft Excel, Word, and PowerPoint, PDFs, JPEGs, MPEGs, Zip files, compressed data streams, and even some databases). The data reduction benefits in these cases are negligible. It's like attempting to zip a zip file. Sometimes the end result is larger than the original.

File deduplication

File deduplication is very strong at reducing duplicate VMware .vmdk files, especially ISO and template files such as virtual desktop infrastructure (VDI) templates. It is also strong in content-addressable storage (CAS) where files must have proof (usually hash marks) they

haven't changed from the time they were stored for compliance reasons. By limiting data reduction to identical files only, it preserves each unique file in its entirety.

File deduplication is not the best choice for storage reduction. It does not reduce duplicate data that may reside in multiple files or files that vary slightly from the original. There is also a rehydration penalty when the deduped data is read or restored.

Block/variable block deduplication

Block/variable block deduplication is extremely effective at reducing backed up, replicated or snapshot data. As the amount of deduped data increases within the datastore, so do the data deduplication ratios. The systems that can scale well with raw capacity (not just predicted as effective capacity) will provide the greatest value. It also allows more data to remain on disk before it has to be moved off to archive targets. This makes recovery of that data much faster.

Another strength is with reducing duplicate VMware .vmdk files (ISO, template files, VDI) and duplicate data between .vmdk(s).

However, block/variable block data reduction must first be rehydrated when moved to other types of storage, such as tape, optical or even another target disk storage device. It also adds noticeable time to the restoration of backup or snapshot data. Though there are exceptions when performance is irrelevant, the additional latency usually makes it

unacceptable as primary storage for many applications because of the decreased response times.

Additionally, like file deduplication, block/variable block is not very effective with already compressed and/or encrypted data, and will not dedupe data it does not see.

Delta block optimization

Delta block optimization reduces the amount of data being backed up or snapped. This reduces the amount of storage and bandwidth for ongoing data protection.

What it doesn't do is reduce the blocks of data that may be duplicated in different servers or even files, even though it is backed up by the same software and stored in the same data store. Some backup software has artifacts in the code because it was originally written for tape backup. It may require a periodic full volume or synthetic (virtual full volume backup) backup, significantly reducing the overall benefit.

Application-aware deduplication

Application-aware deduplication is the most effective data reduction for primary storage because it's so successful with compressed files while adding nominal file rehydration latency. However, this technology requires a "reader" or a filter that runs either on the application or in the NAS to enable the nominal file rehydration latency. It also requires an appliance that looks at the datastore, performs all of the application-aware dedupe after it is first written to the data store, and then provides the ongoing meta data.

"In-line" deduplication

In-line dedupe requires less storage than post-processing deduplication because it is deduping before the data is written to the data store.

Unfortunately, its maximum performance tends to decrease as the target approaches its limits because as the data store increases, so does the database that is being compared to the incoming data. Eventually, there is diminishing marginal returns where performance degradation is greater than the increased benefits of a single data store. The one exception to this is the NEC Corp. HYDRAstor grid architecture that allows processing nodes to be added independently of the capacity.

"Post-processing" deduplication

Post-processing dedupe allows streaming data to be accepted by the data store at much higher speeds than in-line. This is especially effective for virtual tape libraries where the backup window (performance) is more important than the extra savings in storage. It also allows application-aware dedupe to work with primary storage and have zero impact on

write performance. The downside is that all of the data must first be written before it is deduplicated, meaning more disk storage is required than in-line.

Backup software

Deduplication can be found in six different backup software packages, including Asigra Inc.'s Televaulting, CommVault Simpana, EMC Corp.'s Avamar, Hewlett-Packard (HP) Co.'s Data Protector, IBM Corp.'s Tivoli Storage Manager (TSM) and Symantec Corp.'s NetBackup Pure Disk. These packages allow any data storage to be the target storage do not require

specialized high-priced dedupe storage or appliances. This means fewer storage vendors and less hardware or systems to manage.

While the deduplication capabilities are typically included in the software with little to no license fees, the downside is that it tends to create backup software lock-in (difficult to migrate data between backup software products). In some cases, a different agent has to be installed. Asigra's offering is the exception to this since it requires no agents but requires either physical or virtual server appliances on each LAN segment to be backed up.

NAS appliances/target storage

Deduplication is best known as a NAS appliance or NAS system. The key advantage is that this type of storage target can be added to the current backup infrastructure with minimal changes while receiving immediate benefit. It tends to work with most of the primary backup, server replication and snapshot software packages on the market today (with the exception of dedupe and/or encrypted backup software).

The downside is the inverse of the backup software that it tends to lock-in the dedupe storage hardware vendor. It is complicated migrating data to other data stores. The primary storage vendor is often not the dedupe storage vendor, adding another system and vendor to manage.

VTL deduplication

Virtual tape library (VTL) deduplication systems are ideal candidates for environments that backup to tape today, while requiring faster backups, restores, at a lower cost. VTL

deduplication makes that possible with zero changes to the backup methodologies.

The downsides may include an inability to export to real tape. VTL dedupe also can't save much in actual tapes because deduplication must be rehydrated before moving to actual tape (Sepaton's product doesn't have this issue because it scales very high and doesn't export to tape). There is also a lack of integration with all of the media servers and, overall, VTL dedupe is a temporary solution.

Best practices for using server virtualization in

your storage environment

By: Rick Cook

Server virtualization can lower costs and increase capacity on physical servers by sharing them among several virtual machines. However, there are a number of best practices to consider when using or thinking about server virtualization.

When using virtualization systems from VMware Inc. and other vendors, it's important to remember that there's a physical server with physical storage underneath the virtualization layer. This means that you still can't exceed the capacity of your basic hardware, and virtualization will give you less total capacity because of the overhead of the system. So while you can balance your load by putting applications with different peak loads on different virtual machines (VMs), you must still respect the limits of your hardware.

Because of this, server virtualization software requires a slightly different set of best practices when there are problems with your storage subsystem.

Poor I/O can impact the system

The most critical factor in a VMware installation is generally bandwidth. The I/O

performance of your physical system will have more to do with the overall performance of the system than the storage capacity.

Anything that degrades I/O, such as a failed disk in a RAID array, will have a major impact on the performance of your virtualized system. If you're having performance issues, one of the first things you should check is I/O. For example, RAID arrays should continue to work even with a bad disk, but they will slow down considerably and likely affect your virtual machines as well.

Monitor virtual machine performance

Virtualization introduces a whole new level of performance statistics. In addition to being concerned with the performance of the underlying physical hardware, you now need to pay attention to the performance of individual virtual machines.

Fortunately, VMware can monitor a number of statistics to measure the performance of your virtual machines. For tuning and troubleshooting purposes, you should be familiar with these numbers, particularly disk command aborts and memory in and memory swap-out.

Disk command aborts are requests that have timed out because the disk is taking too long to respond. This indicates a problem such as an I/O bottleneck or a poorly configured disk.

Memory swap-in and memory swap-out each measure activity in the virtual machine's virtual memory. A large number of memory swaps indicate that the VM doesn't have enough memory and its parameters need to be adjusted. It's important to note that this refers to memory assigned to the VM, not necessarily physical memory.

VMware's vCenter Server can help you make the most of server virtualization statistics. With this tool, you can maintain logs going back five years as opposed to the one hour maximum that the VMware ESX and VMware ESXi platforms provide.

Eliminate single points of failure

The failure of a single piece of hardware can take down a dozen or more virtual servers. To correct this, storage managers should carefully plan their storage infrastructure and

eliminate single points of failure in their physical infrastructure. This includes such features as redundant data paths between the physical server and storage system, multiple host bus adapters (HBAs) on both ends of the storage-area network (SAN), and RAID or even

Ensure the write cache works properly

Because I/O is so important to virtualized systems, you need to ensure that the write cache on your RAID controller is working properly. For example, a dead or missing battery on the controller card can disable the card's write cache, which will lead to problems with the RAID controller.

About EMC and your local EMC Solution Provider

About EMC

EMC Corporation is the world leader in products, services and solutions for information storage and management that help organizations extract the maximum value from their information, at the lowest total cost, across every point in the information lifecycle. We are the information storage standard for every major computing platform and, through our solutions, serve as caretaker for more than two-thirds of the world's most essential information. We help enterprises of all sizes manage their growing volumes of

information—from creation to disposal—according to its changing value to the business through information lifecycle management (ILM) strategies. EMC information infrastructure solutions are at the heart of this mission, helping organizations manage, use, protect, and share their information assets more efficiently and cost-effectively. Our world-class

solutions integrate networked storage technologies, storage systems, software, and services.

Find an EMC Partner near you!

About Content Archiving Solutions

Geographic Coverage: Massachusetts, New York (upstate), Rhode Island

Content Archiving Solutions provides comprehensive data management solutions for customers in various industries including financial services, manufacturing, governmental agencies and schools. CAS designs custom information infrastructures with best of breed technology focused on backup, recovery and archiving, virtualization and consolidation.

CAS employs a customer focused approach to solution development that incorporates the following methodology:

Problem definition and risk assessment Assessment based on onsite data gathering Analysis and summary of findings

Strategy to achieve long term goals Comprehensive implementation

Health-check to validate problem resolution

About ESTI

Geographic Coverage: Saskatoon, Regina, Winnipeg

At ESTI, we have worked diligently for more than 20 years to make the development of professional staff our core competency. We have established the premier IT Infrastructure team in the prairies. Our staff bring technical capability, longevity in the field, and an intense focus on client requirements. Our goal is to establish a lasting relationship with customers and thereby drive business benefit, both for our clients and for ESTI. We

understand the risk inherent in IT Infrastructure projects and work carefully with our clients to minimize the technical risk involved in their projects. We engineer solutions that we know will meet our client’s project requirements.

We think of ourselves as a provider of IT solutions. Our solutions bring more value to our clients than can be achieved with a simple product or service offering. To facilitate solution delivery, we have established deep relationships with a select group of vendors. We work closely with these vendor partners to provide solutions for our clients. Professional services are a key success factor in our IT Infrastructure Solutions. Our technical professionals provide assessment, architecture, deployment, and quality assurance services. ESTI deploys the professional services of our vendor partners alongside our team where special skills are required.

About M&S Technologies

Geographic Coverage: Texas, Oklahoma, Louisiana and Arkansas

M&S Technologies is a Network Security Value Added Reseller (VAR) headquartered in Dallas Texas. M&S Technologies offers an array of state of the art technologies and solutions to meet the most demanding requirements of IT environments. Whether your business is local, national, or global, M&S is here to help. M & S' Security Practice incorporates industry best practices and methodologies to create plans, processes and policies that enable organizations to manage and control their information security risk by assessing their current security environment and developing a capability to respond to and recover from disruptive security threats. M & S specializes in securing the critical

components of your environment. As Network Security Experts, we have a highly trained team of engineers who will work with you to assess your needs and come up with a solution to solve your security and networking issues. With a world of threats ready to impact your business, our clients rely on us to deliver peace of mind for their security needs.

About Pride Technologies

Pride Technologies is a leading information technology and business solutions firm that brings innovative and highly customized solutions to the marketplace. Pride Technologies is one of the oldest minority-owned IT firms in the US with regional headquarters in

Cincinnati, Ohio. Leveraging more than 25 years of experience Pride has enhances its core competency of IT consulting services by creating client-centric solutions to address the most critical and complicated business challenges. Pride Technologies serves fortune 100 clients offering Virtualization Solutions, Infrastructure Optimization and Automation, Business Continuity, Data Management and Consulting Services.

About Solutions II

Geographic Coverage: Colorado, Utah, Washington, Nevada, Texas

Solutions II, started in 1992, is an Information Technology consultant nationally recognized for world class innovation in Virtualization, Business Continuance, Storage Optimization and the security issues related to these disciplines. Solutions II also hosts a Cloud Enablement Group.

This group assists clients in leveraging virtualization and related technologies and services to drive the cost out of IT Infrastructure, increase performance and optimization of IT resources while ensuring system availability, system recovery, security and compliance within current regulations. Solutions II's commitment to bringing best-of-breed solutions to clients includes a professional services practice dedicated to increasing customer service levels and decreasing the time and support required for implementations to keep their clients "Performing Ahead of the Curve."

About Steelhead Data

Geographic Coverage: Northern California, Nevada, Portland OR

Steelhead Data is a market leader in systems integration, with a strong focus on partnering with our clients to find the best possible virtualization solution for their business, helping apply the principles of virtualization to storage, networking and disaster readiness. We embrace the whole process from assessment through implementation and beyond, to encompass training, support and consulting. Our purpose is to provide the best technology infrastructure, encompassing, hardware, software, services and expertise in both the virtual and traditional environments. Steelhead Data is your virtualization partner, with proven solutions, and the ability to produce a viable proof of concept for your business. The value we deliver is evident in our well established relationships with technologically savvy

customers and our world-class technology partners. We offer an unparalleled depth of expertise in virtualization, best-in-class technologies, and end-to-end solutions. We are committed to customer satisfaction at all stages of the solution lifecycle.

http://www.steelheaddata.com/

About WebPoint IT Solutions

WebPoint IT Solutions is one of the fastest growing IT solution providers in Eastern NC. We offer outsourced managed service solutions to businesses and customized support solutions based on customer requirements and business functions. From simple PC support to sales, implementation and service of Dell, HP, EMC, and VMware business solutions, to managing your IT department, WebPoint IT Solutions has the employees to handle your IT needs while letting you focus on running your business.

In November of 2007, WebPoint IT Solutions moved its server farm into a secure data center in Raleigh. Our Data Center provides our customers with a high availability internet connection along with redundant internet and power connections. Today that Data Center host over 100 of WebPoint IT Solutions and its customers’ virtualized servers. In 2008, WebPoint IT Solutions partnered with EMC & VMware to provide sales & service for virtualization, storage, backup solutions, archiving, and disaster recovery.

Today with over 35 employees WebPoint IT Solutions provides one of the largest IT staffs in eastern NC, and brings a “proactive” method of managing systems and networks instead of the traditional reactive mode. Allow WebPoint IT Solutions to become your IT resource partner so you’ll have more time to manage your business.