A viable data storage option for SMBs is a storage area network kit. A SAN kit --- a so-called "SAN-in-a-box" --- provides a relatively cheap and easy way to install a basic storage area network device in a small business. They are especially attractive to companies with minimal SAN experience and little or no dedicated IT staff. In addition, managing all your storage on one network also cuts down on housekeeping chores and other administrative tasks over server-attached storage.
SAN kits are offered from vendors like Hewlett-Packard (HP) Co., Hitachi Data Systems and IBM Corp. They often come with special software wizards for easy setup, and the prices range from $10,000 to $20,000. Generally the kits are considered about as difficult to install as another server, but not nearly as much as a conventional SAN. An administrator with little or no data storage experience can get them up and running in short amount of time because each of the kits come with special software wizards designed for easy installation.
Besides the special software wizards, each of these kits typically includes a SAN switch, host bus adapters (HBAs), cables and setup software to establish a complete SAN. Some include the array and drives, but these require a separate purchase if they aren't included.
You also need to make sure that your kit is compatible with your servers and arrays (if you're providing them). Some SAN kits are designed to work only with a specific line of servers. For example, IBM's TotalStorage DS400 only works with IBM's e-server X Series. QLogic's SAN Connectivity Kit is designed to work with EMC storage arrays. Other SAN kits can be more general with the types of servers they are compatible with.
These kits will generally support virtualization using either VMWare or Microsoft's virtualization features.
iSCSI vs. Fibre Channel SAN-in-a-box kits
SAN-in-a-box kits are available in either Fibre Channel (FC) or iSCSI capabilities. Some companies, such as HDS, offer both versions. Speeds range up to 8 Gbps for FC SANs and 10 Gigabit Ethernet for the iSCSI models. Generally, the faster the kit, the better they work, but that means they are also more expensive.
ISCSI and Fibre Channel SAN kits both have pros and cons associated with them. ISCSI uses Ethernet so it is more familiar to most people. It used to be that FC was faster than iSCSI, however with the advent of 10 Gigabit Ethernet (compared with a maximum of 8 Gb Fibre Channel), that's not necessarily true any more. However, iSCSI has more network overhead because of the need to bundle and unbundle SCSI commands in IP packets for transmission over the Ethernet.
Although ease of installation with SAN kits is typically a wash, iSCSI kits are generally cheaper than Fibre Channel because the network components are cheaper.
If you decide to go with an iSCSI SAN kit, be sure to configure it on its own subnetwork or at least a virtual private network (VPN). iSCSI SANs don't mix well with conventional Ethernet LANs and the performance of both can be compromised.
Buying a SAN-in-a-box kit
Ease of installation is typically the major selling point for SAN kits. They are designed to be as simple as possible to install and the software usually includes wizards to configure the SAN and guide you through the process. The manufacturers boast that a SAN-in-a-box can be set up and running in an hour or less. While that may be stretching it, especially for a user with no SAN experience, it is true that such simple SANs can be set up very quickly.
Relatively low price is another advantage of SAN kits. Most of these kits sell for between $10,000 and $20,000, which is inexpensive for a SAN, especially if you include the cost to set up and configure a conventional SAN.
Because the SAN-in-a-box kits are so simple, they are typically sold over the internet. However, you can also purchase them from VARs or consultants. You should consider going through a VAR or a consultant, especially if you're not sure you can install the SAN without help.
The only downside to these SAN-in-a-box kits is that they are very simple SANs. But keep in mind that you can expand them by adding additional disk arrays. These kits can potentially connect to up to 16 servers, depending on the number of ports, but most go up to four or five servers. Also, they can configure several terabytes of storage depending on the size and number of disks, and support SATA, SCSI or Fibre Channel, depending on the vendor. Most of them will also auto-configure to RAID 5 or other RAID levels, at the installer's option.
While the kits stress ease of installation and management, they don't eliminate the need for planning your SAN. You still have to decide how to divide your disk space for best performance and reliability.
While a SAN-in-a-box is not a good choice for larger enterprises because of the limits on scalability, particularly in heterogeneous switch environments, they are definitely worth exploring for smaller businesses with more limited needs.
About this author: Rick Cook specializes in writing about issues related to storage and storage management.
This was first published in June 2010