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2006 Introduction Network Administrators are finding the need to provide more cost effective Return on Investment (ROI) for their IT infrastructure with fewer resources. More companies are looking at Storage Area Networks (SANs) to address the mid- to long-term storage needs of businesses from the Small & Medium Business (SMBs) to the large Enterprise. SANs provide all the right ROI tools such as centralized management, storage pooling, and both capacity and performance scalability. In the past, SANs have been based around fibre channel (FC) storage, wiring and switches. These SANs leverage large high-performance Fibre Channel Storage Arrays for the fortunate few application servers that are connected to FC SANs. So, why doesn t every business deploy a FC SAN? Many SMBs simply cannot afford to deploy Fibre Channel SAN infrastructure for a range of reasons that start with cost, interoperability issues, shortage of FC SAN management expertise and tend to end with complexity. Only recently have two trends made it possible for SMBs use a SAN infrastructure. These trends are iscsi (Internet Small Computer Systems Interface) and the recent availability of affordable large arrays based on SATA technology. iscsi enables IT departments to deploy an IP SAN based on their current LAN and WAN architecture. Today, the penetration of Ethernet in both SMBs and Enterprises approaches 100%. However, only about 20% of companies (that tend to be large Enterprises with centralized data centers) deploy Fibre Channels SANs. Recent advances in SATA disk-based technology are providing "Next Generation" performance, reliability and high data availability that serves the requirements of most demanding applications at a fraction of the cost of Fibre Channel storage arrays. SATA is appearing alongside Ultra320 SCSI and Fibre Channel disk at less than a dollar a gigabyte. Yet SATA can provide similar performance to the more costly SCSI or Fibre Channel RAID subsystems. StoneFly provides the tools and the enabling piece of the architecture to provide these new types of SANs. StoneFly's Storage Concentrators are IP-based storage provisioning appliances that enable management and optimization of storage assets in real-time. Combining an iscsi router and bridge with the power of a storage provisioning engine, Storage Concentrators are installed at the core of the network for logical volume management. By utilizing Ethernet network infrastructure, Storage Concentrators can optimize large arrays across appropriate IP SAN Application servers such as SQL, Exchange and File Servers. The Storage Concentrator can provision existing deployed storage and/or newly acquired cost effective large RAID arrays across Ethernet networks as logical iscsi targets. These iscsi targets will appear as locally attached disks to the Application servers. iscsi allows currently deployed operating systems, file systems and applications to work with these logical volumes at block level speeds. Let s look at an example below. Page 2 of 7
Current Infrastructure: Many SMBs have a dedicated 10/100/1000 Ethernet LAN for file level activity such as SQL, Exchange, printing and general file sharing activities between the Servers and desktop workstations. They usually have four to six Windows Application servers that share different application loads such as Dbase (SQL, Oracle, SyBase, DB2 etc), Email (cc:mail, Exchange etc), DNS/Active Directory Server and basic file sharing (Windows Storage Server 2003 File Server). The following diagram showing just two Application servers represents the example indicated above: IP SAN Deployment: One way to deploy an IP SAN is to place a dedicated 10/100/1000 Ethernet switch behind the Application servers. A StoneFly Storage Concentrator could then be deployed on this dedicated 10/100/1000 Ethernet IP SAN. Each Server could use generic 10/100/1000 NIC cards with iscsi software and/or dedicated SNIC (Storage Network Interface Card) hardware. The diagram below represents this. StoneFly s complete line of simple, affordable Storage Concentrators are based on the company s patent-pending StoneFusion storage networking architecture that intelligently optimizes storage assets, offering the functionality traditionally associated with expensive midrange and high-end storage systems, and host-based volume management software. The StoneFusion architecture includes: An in-band metadata storage-mapping layer that presents physical storage devices as a common storage pool Intelligent iscsi storage packet routing software, providing aggregation and bi-directional data transfer for increased throughput Page 3 of 7
A relational database that tracks physical data locations to ensure data integrity Online storage management to easily consolidate free storage space maximizing storage resources Extensibility that allows additional storage management applications to simply be plugged in without additional host agents A typical SMB environment may optimize a one to six TB SATA RAID array behind a StoneFly Storage Concentrator FailOver Cluster. A Storage Concentrator i3000 FailOver Cluster consists of a pair of Storage Concentrators configured with one managing storage volumes, and the other operating as a redundant system monitoring all fault conditions. This ensures storage volumes are protected and continuously available to guarantee customers high availability and business continuity in their IP SANs. An IT administrator could create one large RAID 5 logical LUN on the new RAID using 8 250GB serial ATA disks. Or the administrator could create several logical LUNs across different physical drives, which typically reduces overall performance due to fewer disk spindles per RAID LUN. Creating logical LUNs across different physical Page 4 of 7
devices may create further overhead depending on the efficiency of the RAID system s software and hardware architecture. The Storage Concentrator can take a single large logical LUN and carve it in to smaller logical volumes that are seen as iscsi targets by the application servers using iscsi initiators. These StoneFly logical volumes are seen as local hard disks by the Application servers, which can then leave them raw or apply an appropriate file system depending on their own specific requirements. An IT administrator is then able to create the appropriate size logical volumes for the application servers with out any further RAID logical LUN configuration and/or management. Leveraging Application Performance with an IP SAN It is very important to ensure that the IP SAN provides not only the usual SAN benefits, but also adequate Application server performance. IT Administrators must be able to quantify the minimal and acceptable performance requirements from any disk I/O subsystem. Whether you are using SCSI, Fibre Channel and/or serial ATA, the RAID controller s performance is usually determined by a range of factors, such as file system, available host memory, CPU, application I/O data patterns, and the type of PCI bus to the storage systems. Typically, SMBs have deployed internal drives that are mirrored. These tend to provide 8-10 MB/sec at around 200-300 I/O s per second for the database, email and file application servers. A Storage Concentrator deployed in an IP SAN configuration and leveraging the new SATA RAID technology is able to provide up to ten times this I/O performance for a single application server. When scaling beyond one server, each shares an equal percentage of performance that is in proportion to the number of servers attached. For example, six servers on the same IP SAN pulling or pushing the same data patterns and data size would expect to see the equal amount of performance at approximately 8-10 MB/sec this is about 80-100MB/s aggregate performance. Page 5 of 7
Optimizing Existing Storage in an IP SAN Many SMBs find that they have redundant older storage that has been replaced by large capacity or high-performance storage devices. Today, StoneFly allows IT departments to utilize these redundant pools of disks on to new IP SANs, where they can used be for non-critical data such as disk-to-disk backup applications. An IT administrator simply deploys the Storage Concentrator on to an existing or dedicated Ethernet LAN. They can now leverage their legacy SCSI/ Fibre Channel JBOD/RAID storage devices. Once attached, they create logical volumes that can be deployed to desktop workstations and/or application servers via the Storage Concentrator. As shown in the diagram below, each server has its own dedicated logical volume so that exchange data is stored in the exchange server s logical volume and the SQL data is stored in an SQL logical volume, and so on. Leveraging Fibre Channel Storage on an IP SAN Page 6 of 7
Large enterprise data centers can carve and provision logical LUNs to a StoneFly Storage Concentrator from their currently deployed Fibre Channels SANs. A typical example would be breaking an existing third mirror span on a three-way mirror to redeploy this data to application servers on a StoneFly IP SAN. In the diagram above, Span 3 appears as one large disk to the Storage Concentrator. However, the Storage Concentrator has provisioned the data into logical volumes for each of the Application Servers. Conclusion: Optimizing Large Arrays As seen in the above examples, the IT departments in SMBs and Enterprises now have the opportunity to redeploy redundant storage devices and/or pools of Fibre Channel SAN storage across IP SANs. These IP SANs are able to provide the benefits of FC SANs and optimize new and old storage devices when utilizing StoneFly s Storage Concentrator solutions. Page 7 of 7