An iSCSI Primer
iSCSI (pronounced "i-scuzzy") is an Internet Protocol (IP)-based storage networking standard for connecting storage arrays to computers, using high performance Ethernet. iSCSI is an industry-standard protocol, allowing organizations to consolidate storage into data center storage arrays while providing hosts (such as database and web servers) with the illusion of locally-attached disks. Unlike traditional Fibre Channel, which requires special-purpose cabling, iSCSI can be run over long distances using the existing network infrastructure. | |
File-sharing protocols, such as SMB and AFP, are convenient for networking a storage device to many clients (e.g. to share a Microsoft Word document), but often do not have the efficiency or performance expected in business environments (e.g.. to operate SQL Server). That’s why iSCSI was invented.
iSCSI is High Performance
For demanding applications such as Microsoft Exchange, Microsoft SQL, or high-definition video editing, the iSCSI protocol is an ideal solution for providing high-throughput reads and writes. iSCSI is efficient because it is a block-level protocol.
Performance Anywhere and Lower Costs
The big advantage of iSCSI is that it can be run over existing switching and IP infrastructure. However for the best performance it is recommended that you operate iSCSI on a dedicated network or subnet (LAN or VLAN). You can also connect a DroboElite or DroboPro directly to a server with a network cable, bypassing network switching and VLAN configurations entirely. As a result, iSCSI is seen as a very low-cost alternative to Fibre Channel.
Windows and OS X Support
DroboElite and DroboPro support zero-click iSCSI connections on both Windows and OS X. For Windows, Drobo Dashboard, the management software included with Drobo Elite and DroboPro, uses Microsoft’s iSCSI software (“initiator”). However, OS X does not natively contain iSCSI support. Thus, Drobo Dashboard includes the necessary iSCSI software initiator for OS X — free of charge.
Understanding iSCSI vs. NAS
There are important differences you should understand between iSCSI and network attached storage (NAS).
- iSCSI is ideal for high volume data storage traffic and is designed to be a direct block-level protocol that reads and writes directly to the disk array. NAS-level protocols read and write at the file level, which means the disk array needs to perform more translation effort to actually access the blocks of data on the disk array.
- In most scenarios, DroboElite and DroboPro can be connected to your existing networking infrastructure. For the best performance in this configuration, it is recommended that you segment iSCSI traffic by creating a VLAN dedicated to that traffic. This will keep your high volume data storage traffic segmented from the rest of your LAN traffic. You can also attach multiple DroboElite or DroboPro storage systems to one or more than one host via this same switch setup.
- For optimal performance you can also directly attach DroboElite or DroboPro to your host, as shown below. This assumes you have more than one networking port on your server that you can dedicate to a DroboElite or DroboPro.
- Each DroboElite and DroboPro will need its own unique IP address that you configure using the Drobo Dashboard software that comes with each Drobo storage system
- There are dozens of specific features that have been layered on top of the iSCSI protocol over the years. In other words, iSCSI can be a complex jungle, but you’ll find deploying iSCSI with DroboElite and DroboPro to be simple and straightforward. In fact, DroboElite and DroboPro with Drobo Dashboard connect to your server with a single click of the mouse.
If you're wondering whether or not DroboElite or DroboPro will solve your specific needs and/or you have technical questions, please contact Data Robotics Pre-Sales Support at 1-866-997-6268 or at sales@drobo.com. |
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