Virtualisation: a recipe for the simple life

Virtualisation built into an iSCSI storage array delivers cost efficiency, flexibility, simplicity, data protection and scalability which dramatically improve today’s IT operations. Combine that with server virtualisation, and you get a fluid architecture that can further minimise disruption and cost. Storage and server virtualisation go hand in hand with consolidation, a common trend in many IT environments. Storage consolidation means moving data off direct-attached storage (DAS) and onto shared pools in storage area networks (SANs). Server consolidation has become popular recently, thanks to technologies that create 'virtual machines', with which you can consolidate multiple server images onto fewer hardware platforms. For both storage and servers, consolidation and virtualisation make complex, cumbersome tasks easier.

Vive la Difference
Without virtualisation, storage management is a necessary burden to operations and budgets. With traditional DAS storage, IT staff must manage disks individually for every server; expansion and reconfiguration are difficult, disruptive, manual tasks. But storage virtualisation conceals the underlying complexity of tasks such as storage allocation, load-balancing, RAID configuration, back-up and restore. Because they are no longer bound by the physical dimensions of disks, storage administrators do not have to cut up pieces of the storage pie and manually assign them to particular applications. As a result, business applications can grow and change smoothly without disruption, and IT administrators have fewer tedious, manual tasks – saving time, money and staff training, as well as improving productivity. Not all storage virtualisation solutions are equal, but the ones that deliver true flexibility and reduced complexity will improve efficiency and reduce cost.

Similarly, the advantages of server virtualisation and consolidation are clear. Today's IT shops run numerous applications on multiple operating systems (OSs): the simplest deployment method has been to run each application on different server hardware. Unfortunately, the major drawback of this implementation is low server utilisation rates, averaging about 30 per cent. That leaves 70 per cent of the server unused, with IT constantly purchasing and managing new servers while available capacity sits idle. With today's virtual server technologies, OS images and applications are now portable between physical machines rather than wedded to hardware, yet each virtual server maintains its identity to clients. Thus you can now take a 30 per cent-used server and easily move an application from another 30 per cent-used server without downtime, so doubling your utilisation rate, yielding better productivity and lower total cost of ownership.

Working Together Works Best
While each virtualisation method individually improves productivity, deployments which leverage storage and server virtualisation together enjoy significantly greater business benefits: flexibility, cost efficiency and data availability. For example, with virtual servers in a DAS environment, you can move the virtual machine – but you still have to stop the application, execute a lengthy data copying process, and restart the application. However, with virtual servers in a virtual SAN, you simply move the virtual machine and resume on different hardware, in some cases without even pausing the application – a much more flexible, fluid implementation that keeps business operations online. Once again, however, not all solutions are the same – only virtual server implementations which are SAN-aware can support advanced SAN features, such as snapshot-based back-ups, multi-path I/O, clustering and SAN booting. If they are not SAN-aware, your virtual servers will act as if they are on DAS, and these advanced features will not be available. To gain maximum business benefits, you need virtual servers and virtual storage working together.

Virtual Infrastructure in a Manufacturing Environment
At EqualLogic, we built virtualisation into our PS Series storage array to simplify storage management, automating tasks such as storage provisioning, load balancing and RAID configuration. Our customer Shiloh Industries, a full-service manufacturer of engineered steel products based in Ohio, built a virtual infrastructure using an EqualLogic SAN and VMware virtual servers. Shiloh’s production operations are distributed throughout numerous plants. With approximately 30 servers running numerous applications on multiple operating systems (Microsoft SQL Server, IBM AIX and Novell Netware), the only way to completely protect data was with daily full back-ups on every server. Unfortunately, this method tends to be unreliable, particularly in branch locations, leaving data vulnerable. In fact, when a power glitch two years ago caused a DAS array failure, Shiloh lost all of its email stores. In addition, the growth of the company was exacerbating the problems of both individual servers and individual storage; tapes were proliferating; aging servers needed replacement at great cost; and the company needed better data protection and disaster recovery for its multiple locations.

Shiloh's IT staff decided that virtual servers and storage could work together to solve their problems. Together, these virtualisation technologies would simplify management tasks, provide a flexible infrastructure, and ease management burdens. VMware was selected early on as a stable and robust product that would support the multiple operating systems in use. After evaluating numerous Fibre Channel and iSCSI storage solutions, Shiloh chose EqualLogic’s PS Series iSCSI SAN, in part because of all the functionality built into the array. Advanced features such as snapshots, auto-replication and load balancing are included in the array’s firmware; other more expensive solutions required purchase of costly software modules to attain advanced features. In addition, the PS Series array includes automation that other arrays do not, designed to ease the burden on storage administrators.

Shiloh's infrastructure now includes two EqualLogic arrays in their primary data centre, one at another plant and one in a disaster recovery site. Their VMware implementation enabled them to go from 30 physical hosts to five. Applications now run on 30 virtual servers hosted on only five physical servers, each with high-performance access to the EqualLogic SAN. With this virtual infrastructure, they avoided the expense of replacing all their ageing servers. Shiloh can now quickly deploy additional servers as needed. In addition, a clustered file system from Sanbolic spans the physical servers, simplifying rapid migration of virtual servers between physical hosts. Each virtualisation technology contributes to the flexible operation of the others as they work hand in hand for efficient operations.

Data protection procedures are significantly improved with this virtual infrastructure. Nightly full back-ups at all remote locations are no longer required; with replication capability, changes are mirrored to a central location from which tape back-ups are created and centrally managed. Non-disruptive, online snapshots of each virtual server’s system and application data are maintained for immediate data recovery and are used as the back-up data source.

Today, Shiloh's multi-OS, multi-application, multi-location environment operates efficiently with its EqualLogic SAN and VMware virtual servers. Virtualisation has given Shiloh the flexibility to grow efficiently and significantly improve data protection, productivity and cost efficiency. Says Steve Meckling, network services administrator: “The central piece of our infrastructure is the EqualLogic SAN, and everything revolves around that. With virtualisation and the automation and advanced features of our PS Series arrays, we have built an environment that easily integrates growth and change with maximum production time and lower costs.”