Monday, December 20, 2010

George Crump, Senior Analyst

What Are SMB Server Bundles?

SMB server bundles are turnkey versions of the respective operating systems preinstalled on server hardware. They often preconfigure many of the more difficult networking settings for the users and provide step-by-step wizards to complete the installation. As stated above they will include the common core applications that a small business will need as it first moves to a server hosted environment. The set up of these applications are also wizard driven allowing the SMB to bring them online without needing a great deal of expertise.

The SMB server bundles are offered at very aggressive pricing, but the manufacturer often restricts the number of users they support, for example up to 10 users. Those initial licenses are often a sufficient starting point for most SMBs. This is the tradeoff for all of the functionality that would otherwise cost much more in unlimited versions of the OS, or if the software pieces were purchased separately.

Another limitation of these preconfigured hardware platforms is that they often lack sophisticated connectivity for attaching to shared storage. Most do however, include at least one 1GbE port and many include two. This is an ideal use case for an iSCSI based storage system like DroboPro or DroboElite, as they do not require additional hardware to be installed in the server. In the case of a single onboard GbE port, users can include a dual-port GbE NIC pre-installed with their purchase of small business server hardware for <$200.

Shared Storage Drivers For The SMB

Since these bundles encourage the SMB to move into a server-hosted environment sooner, they also hasten the need for shared storage as well. Shared storage is an appliance of one or more hard disk drives that exist on a network, allowing for access by multiple computers. There are typically three key drivers for buyers of SMB server bundles to quickly add shared storage. First is a simple case of additional capacity. Most of the servers that are included in these bundles are physically small in size and as a result are limited by the amount of internal hard drive capacity that they can support. They often only have room for two hard drives. Also because of the dense packaging of these systems, getting inside the systems to add the hard drive may be too much effort. Shared storage via an iSCSI connection through one of the 1GbE ports is a simple way to add capacity without the headache of opening and reconfiguring the server.

Second, as the server quickly becomes a critical asset to the organization, making sure that the data it stores remains available becomes vital. Unlike the laptop or desktop environment that they are transitioning from, multiple users, some external in the case of a web application, are counting on that server to be up and running all the time. This is of course one of the reasons that the server is implemented in the first place, to provide a dedicated machine to a specific task within the organization that needs greater availability and access. Consequently, it makes sense that the storage device is up to the task.

One of the most likely components to fail in a server is the hard drive itself. Internal storage systems can only do so much to provide this protection. The servers used in these bundles are almost always configured with basic desktop-class hard drives, which have lower reliability and performance than their enterprise-grade equivalents. It’s important to understand that these are the beginning steps in building a data center, and it makes sense that those steps are made with high quality drive technology.

In many cases small business server hardware can only provide drive mirroring (data kept identical on two drives), which reduces available capacity by 50% and makes future internal expansion complicated. Shared storage systems that are externally attached via an iSCSI connection like those from Drobo can provide advanced RAID protection across up to 8 drives. These storage arrays can be configured to provide access to data even if two drives fail at the same time. This works without having to sacrifice as much drive capacity to the protection process as mirroring does.

Finally and potentially most important, is the ability for the SMB to leverage server virtualization, for which shared storage is a key enabler. Once an SMB implements their first server, the expansion to having a second, third and maybe even fourth server is relatively quick. Sever virtualization allows the SMB to host those four servers on just two physical systems to keep costs down. In fact, most of the servers used in the SMB operating system bundles are usually capable of handling 5 or 6 virtual servers, with each of them running a specific SMB-class application.

Shared storage enables the SMB to achieve higher levels of application availability by being able to move server resources between the two physical systems in case of server maintenance or even failure. It also provides an excellent platform for the SMB to continue to scale server growth without having to continuously purchase additional server hardware. Virtual server mobility between two physical servers requires shared storage.

For more details on the advantages of shared storage and server virtualization for the SMB see the white paper: “No Compromise, Cost Effective, VMware Storage for SMB”.

What The SMB Needs In Shared Storage

As stated earlier the IT administrator at an SMB is often a single person wearing multiple hats with a long daily to-do list. In many cases some of those hats aren’t even related to IT. They need a shared storage system that’s similar to the server bundles that it will support: cost effective, simple to operate and easy to expand.

Even enterprise class hard disk drives though, are still susceptible to failure. If a drive does fail, the time it takes to replace it and recover data from a backup may be too long. Data recovery is always a challenge, even in large companies. But, the effort required is even greater for the SMB IT person who has multiple hats to wear and a hundred other things to do. The answer is to provide a level of drive redundancy, but the server hardware often used in these bundles, as stated earlier, are limited in the number of drives they support.

For a modest additional investment up front, buying a SAN for the small business server up front enables the expansion to multiple servers without the need to purchase additional storage.  A directly-attached storage array can provide the RAID protection needed by the small business server better than internal hard drives can alone, but DAS cannot be shared between servers, and does not support virtual server mobility. It may be difficult to justify an additional $2000 for a starter SAN up front, but that investment is immediately paid back when it comes time to add the next server.

A key requirement is to leverage what the SMB server is likely to be configured with for storage connectivity. In almost every case this means using the Ethernet port. There is a storage protocol designed specifically for that port called iSCSI. It allows storage I/O commands to travel over an Ethernet connection. This makes it easy for the SMB to set up and configure their first storage network using the same Ethernet network that they are using for networking the servers themselves. Drobo makes getting started with iSCSI even easier by providing an installation disk that provides a turnkey implementation. It reduces the amount of IP network configuration to an absolute minimum and moves the user quickly to creating volumes and assigning them to servers.

Another key requirement is the ability to add capacity automatically without having to reconfigure the storage or the attached servers. Both of these tasks can be very complicated with a traditional storage system. At the server level most entry-level storage systems hard-provision storage to the server, which means that the assigned capacity can't be more than the actual capacity available, making re-assignment of capacity almost impossible. There’s an enterprise feature called “thin provisioning” that allows the storage to be ‘over-allocated’ to the connecting servers. Then, as storage is added to the system the connecting servers can take advantage of the additional capacity, as they need it without interruption. This feature would be ideal for the SMB as well. Systems like the DroboElite provide that capability without any setup or administration.

A big challenge for many storage systems, whether designed for large or small business, is the process of adding storage. Some just can't, for some it’s physically complex and for others it’s software complexity. For traditional RAID, drives of the same size are required to expand. In most cases the additional capacity is only available from the vendor with specific firmware, which means more time to get the storage and greater expense to purchase.

An exception is the technique that Drobo uses in its systems, which they call BeyondRAID. First, any off-the shelf SATA hard disk will work. Again as stated earlier, care should be given to use higher quality, higher performing drives but these are still cost effectively available from a local computer electronics store. The drives simply install in the front of the unit, not even requiring a screwdriver. Within a few minutes the additional capacity is available. Finally the unit supports thin provisioning, so that capacity becomes available to the servers as they need it.

For the SMB server, this type of shared storage implementation is ideal. It provides the needed capacity, data protection and sharing (the key drivers for SMBs), while curtailing costs and keeping storage management as simple as possible. The combination of cost effective SMB server bundles and a shared storage system like the DroboElite allows the SMB to move to the next level of compute infrastructure that can give them a competitive advantage.