Virtual Servers And Storage A Two-Way Street

It's one of those rare cases where one plus one equals much more than two.

Solution providers adding server virtualization to their practice are finding the need for new storage infrastructures, including implementing new SANs and re-optimizing existing SANs, to be a growing business.

And those with strong storage practices are finding that they can enhance such areas as data replication and disaster recovery with the addition of server virtualization technology.

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The two technologies are starting to feed each other, said Greg Knieriemen, vice president of marketing at Chi, a Cleveland, Ohio-based solution provider.

"As customers add server virtualization, their storage needs ramp up quickly," Knieriemen said. "So storage consolidation is becoming an issue. Before, a midrange company might have had 20 to 40 physical servers in a non-SAN environment. But many companies that don't have a SAN today that are implementing server virtualization are finding they require a SAN to do it."

Kevin Houston, business development manager and virtualization practice manager at Optimus Solutions, a Norcross, Ga.-based solution provider, said having a good storage network in place is a prerequisite to server virtualization.

"Often times the customer doesn't have a storage network," Houston said. "Or they have older technology, in which case we can then help them move to a more robust platform or add new features. And when we talk storage and add server virtualization, we can then start talking about disaster recovery and a second storage network."

Houston said that the opposite is also true: Storage complexity drives server virtualization.

"Customers have racks full of storage, but no backup windows," he said. "So we talk to them about SANs. And as we help them consolidate their storage, we can also show them how their servers are only being used at 3 percent to 5 percent utilization."

While much has been made about the negative impact server virtualization has had on physical server sales, less noticed is the negative impact it is starting to have on the building of SAN fabrics.

Chris Mierzwa, vice president of product management and alliances at Sirius Computer Solutions, a San Antonio, Texas-based solution provider, said that he is already starting to see a cut in the number of storage ports that are connected to customers' servers thanks to a fall in the number of physical servers being installed.

"Port count and fabric complexity is nothing like the nutty growth of a couple years ago," Mierzwa said. "Now everybody has all the ports they need. The main exceptions are companies that never had a SAN installed before."

Storage is growing in terms of the number of spindles and in the consumption of capacity, but that is not where solution providers can make money, Mierzwa said. "Where we make money is in complex virtualization architectures, and how to carve out SANs," he said. "And with virtualization, customers don't need as many ports. Before, we used to sell SAN directors. But unless you are a Wal-Mart, you don't need 256 ports anymore."

Knieriemen agreed that the number of SAN ports is starting to fall thanks to server virtualization. However, he said that SANs are not always needed by midsize companies implementing server virtualization, and that the technology can actually lead to increased adoption of direct-attach storage.

"VMware can work with SAN and DAS," he said. "So we're also seeing more opportunities for companies like Nexsan."

Bryan Champagne, director of storage engineering at TOSS (The Only System Solution), a Framingham, Mass.-based solution provider, also sees increased server virtualization resulting in a smaller SAN port count.

However, Champagne said that by no means lessens the need for SANs, or at least for looking for ways to tie multiple SANs together. "People think SANs are widely accepted," he said. "But they are often very vertical. For instance, a hospital may have a couple of SANs, but they are focused on specific functions such as PACS or radiology."

But while server virtualization is starting to reduce the number of SAN ports needed to handle the server infrastructure, it is still leading to an increase in storage capacity requirements, said Keith Baskin, storage practice manager at Optimus Solutions.

NEXT: Virtualization of IT Staff?

Regardless of whether Fibre Channel or iSCSI SANs are used, a lot of SAN-based storage capacity is required for such functions as data snapshots and virtual server migration, Baskin said.

"One of the surprises I get on a regular basis is how much physical capacity is required," he said. "It also usually surprises people as they roll into a virtual environment. So we're starting to see requirements for data deduplication at the virtual machine level. Virtual machines have a lot of duplicate data. If we can do de-dupe, we can cut the amount of data stored."

Server virtualization is also leading to a change in the staffing requirements of customers as much of an IT infrastructure's routine tasks become more automated, Mierzwa said.

Customers will need more highly skilled people with server migration and related storage expertise, and fewer people to handle routine tasks, Mierzwa said. "There will be increased pressure on people who can handle these solutions," he said. "We are seeing that from customers who expect our people to have expertise in server virtualization, storage and network management. It will be a while before anyone can say, 'move a big database at 3:00 PM, no sweat.'"

However, Mierzwa said, the bits and pieces are starting to come together, forcing solution providers to develop that kind of expertise. "We will need smart people -- and trust me, they are hard to find, I wish I knew where the tree is where they grow -- and will have to get some of our current people to step up and be able to do more with live server migration and the related storage," he said.

Another area where virtualization has the potential to impact storage is the new movement to adopt virtual appliances. Like physical appliances, virtual appliances are servers with software focused on a single task, such as firewall or Web serving.

Vendors are now taking their first baby steps in making virtual storage appliances. For instance, FalconStor, Melville, NY, early last month unveiled the FalconStor Continuous Data Protection Virtual Appliance for VMware, a virtual appliance created under VMware's Virtual Appliance program.

The new FalconStor virtual CDP appliance is a pre-built, pre-configured, and ready-to-run application that sits inside a virtual machine to back up changes to data as they occur, and to offer instant recovery of a problem server, whether physical or virtual.

Knieriemen, whose company installed several of the virtual CDP appliance on 30-day trial periods, said his customers not only liked the appliances, they started asking about how to implement more technology to virtualize their server infrastructure.

Implementing server virtualization leads to a couple of challenges that solution providers must cope with, Baskin said.

For instance, because virtual servers are running during the backup process, they have to be dealt with as if they are open files in the same way that open databases are handled.

"You need to quiesce the virtual machine in order to work with the VMDK (VMware's Virtual Machine Disk Format) file," he said. "For disaster recovery, if you can get the VMDK file to another system, you can recover a virtual server as long as that other system as a copy of VMware ESX Server."

The problem, said Baskin, is getting the VMDK file into a quiesced state. "In the past, you could suspend it, take a snapshot, and then bring it back up," he said. "But that leads to downtime. You have to put the server in the suspend mode. Today, we're seeing a lot of R&D in being able to quiesce the VMDK file and take the snapshot."

When deploying server virtualization, there are two major issues to watch, Houston said.

The first is to plan for adequate storage capacity, and ensure that enough is available well in advance. The second is to have a good backup strategy in place. "With virtual servers, you can reduce the backup time because you are not having to hit as many targets," he said.

The last couple weeks has also seen an upsurge in vendor interest in connecting storage to virtual server environments.

VMware, Palo Alto, Calif., unveiled a new hardware certification program for storage virtualization devices when connected to its VMware ESX Server environments. The program is in addition to its existing hardware certification programs.

Cisco and storage host bus adaptor vendor Emulex last month unveiled a tested storage networking solution combining Cisco's MDS Fibre Channel switches with Emulex's LightPulse 4-Gbit-per-sec. HBAs for VMware virtualized environments.

DataCore Software, Ft. Lauderdale, Fla., unveiled downloader storage software that can run on VMware virtual machines to enable thin provisioning.

STOREServer, Colorado Springs, Colo., unveiled an agent to enable VMware Consolidate Backup to protect VMware environments and enable LAN-free virtual machine backups in VMware ESX Server environments.

Acronis, Burlington, Mass., unveiled a version of its Acronis True Image Echo that allows IT managers to back up and restore both physical and virtual servers as well as allow applications migrate from physical to virtual servers and vice versa.

UltraBac Software, Bellevue, Wash., recently showed a physical-to-virtual server disaster recovery solution that allows the creation of as many new virtual environments as required on a host virtual server. It can be used to do full bare metal restores of failed servers.