By Dave Simpson and Kevin Komiega
The first article in our series of case studies on why users are embracing iSCSI-based IP SANs concentrated primarily on the benefits of iSCSI in virtual server environments (see Users extol the virtues of iSCSI, part 1; January 2008, p. 1). In the second part of our series, we focus on organizations that went with iSCSI for reasons such as performance, consolidation and, of course, low cost.
MisterArt.com: High performance
MisterArt.com is an online retailer that sells arts and crafts supplies, with more than 60,000 products. To accommodate the company’s 80%-per-year business growth, the IT team recently augmented its existing storage infrastructure to meet its anticipated capacity requirements over the next 12 to 18 months.
The company’s existing storage infrastructure consisted primarily of a Dell/EMC CX300-based Fibre Channel SAN. However, for its storage expansion, MisterArt.com wanted to save money while meeting all of its performance requirements which, after testing several iSCSI arrays, led to deployment of an iSCSI-based Dell PowerVault MD3000i disk array coupled to a 15-drive MD1000 expansion enclosure for a total capacity of 9TB in a 30-drive configuration.
For high availability, the storage system was configured with dual, active-active controllers with mirrored cache. The PowerVault MD300i was populated with 15,000rpm SAS drives for increased performance. Another performance booster was the creation of a virtual storage environment that spread I/Os across disks as drives were added.
In addition to the relatively low cost of iSCSI, Marco Nicolayevsky, MisterArt.com’s CTO, says the IT team went for the MD3000i because of its performance benefits. For example, the MD3000i consistently outperformed another, similarly priced iSCSI disk array under evaluation, and in one test the MD3000i delivered almost 5x higher performance (in terms of database transactions per second). And in some application instances, the iSCSI SAN delivers higher performance than the company’s Fibre Channel SAN. Once the iSCSI SAN was installed, MisterArt.com began migrating some back-office applications from the Fibre Channel SAN to the IP SAN.
Although Nicolayevsky and his team did not execute head-to-head performance comparisons between the Fibre Channel SAN and the iSCSI SAN, he says that when they migrated some databases applications (mostly SQL Server) to the iSCSI SAN they noticed an increase in performance. However, he also notes that it was somewhat of an apples-to-oranges comparison because, in the Fibre Channel array the virtual disks were spanned across eight to twelve disks, and in the Dell iSCSI array the virtual disks were spanned across 28 disks.
MisterArt.com’s iSCSI configuration uses only Microsoft’s (free) iSCSI software initiators-not iSCSI hardware host bus adapters/accelerators. -DS
Consumer Contact: Performance counts
MisterArt.com isn’t the only company that migrated to iSCSI primarily for cost and performance advantages. That was also the case with Consumer Contact, a marketing research data-collection firm based in Toronto.
Before deploying an iSCSI SAN, Consumer Contact had relied on direct- attached storage (DAS) arrays from vendors such as EMC and IBM-most recently, an IBM EXP400 chassis with a ServerRAID controller card configured with 14 Ultra320 SCSI drives. But the company was experiencing performance bottlenecks, mostly in the area of disk access times for its employees and interviewers. Typically, anywhere from 200 to 300 users are banging on Consumer Contact’s storage system simultaneously.
Consumer Contact had tried NAS previously, but that approach didn’t come close to solving the company’s performance problems. The company also evaluated a Fibre Channel SAN (based on a Clariion disk array), but that approach proved cost-prohibitive, according to Liam Cunningham, systems manager at Consumer Contact. The solution turned out to be a 16-drive PS3600 iSCSI array from EqualLogic (which is being acquired by Dell).
The PS3600 is attached to a single Linux server. For performance, Consumer Contact added two iSCSI HBA accelerator cards from QLogic. The iSCSI-based IP SAN is isolated from the company’s primary LAN and includes a dedicated Ethernet switch from Cisco. The primary application in the iSCSI environment is the Data And Software Handling (DASH) application.
According to Cunningham, the EqualLogic-based IP SAN eliminated the company’s performance problems, which in turn led to a 15% increase in employee productivity versus the previous DAS-based configuration.
Although EqualLogic is known for the software applications it bundles with its hardware systems, Consumer Contact is not yet using any EqualLogic applications (other than the management software). However, Cunningham says he will evaluate EqualLogic’s replication function in the future for possible deployment in a remote disaster-recovery application. -DS
Law firm: Software included
Law firms face a variety of unique challenges when it comes to storage. Examples include stringent compliance requirements and the need for fast access to files in support of litigation.
Cory Siansky, director of technology for Gilbert Randolph LLP, a Washington, DC-based law firm, says he was tasked with finding a storage platform that could meet his firm’s performance and capacity requirements and fit into a limited amount of data-center space.
Gilbert Randolph has 25 Wintel servers and a mix of Dell and HP storage devices in both NAS and DAS configurations. To improve its disaster-recovery capabilities and reduce operating costs and cooling requirements, the firm looked for a SAN that was reliable and energy-efficient to pair with its expanding VMware ESX virtual-server farm.
“We couldn’t justify the complexity or cost of Fibre Channel,” says Siansky. “Fibre Channel has reliability and speed benefits, but there just wasn’t enough of an ROI for us.”
The biggest source of capacity growth for Gilbert Randolph is in litigation support. The firm ingests hundreds of thousands-sometimes millions-of scanned images of documents in the course of any given day, most of which are .tiff or .pdf files. “Our attorneys need relatively fast response times to documents and the database that supports our data-tagging operations,” says Siansky.
Along with speed, several additional criteria factored into Siansky’s search for a new storage platform as the firm attempted to move from a legacy NAS farm.
“Compatibility with VMware was critical, and we wanted a system with bundled software, replication tools, and no additional license fees,” Siansky explains.
The law firm also had limited cooling resources in its data center. “We have a certain footprint in our data center. Rack limitations made density an issue, and we’ve maxed out the volume of cooling we can pump into the room. That resulted in a short list of candidates. We had to be sure that our spinning disks weren’t going to generate more heat than we could dissipate,” says Siansky.
iSCSI products from Xiotech, Network Appliance, and LeftHand Networks made the law firm’s short list. All three, according to Siansky, had feature sets and configurations that met his needs and all were competitively priced, but the all- inclusive nature of LeftHand’s SAN/iQ software sealed the deal.
LeftHand’s iSCSI SANs are built on a distributed clustered architecture. The SAN/iQ software clusters storage nodes together, aggregating all of these resources into a single storage pool.
Every node in the cluster participates equally in sharing both the workload and capacity of the entire cluster. And each node has its own controller, which means adding more nodes to a cluster increases performance and redundancy along with capacity.
Gilbert Randolph’s SAN has approximately 23TB of raw capacity, with a projected growth rate of up to 5TB per year. “We’ll have close to 20TB of usable space by the end of 2008. We may only need about half of that to run our operations, with the rest being used for incremental restore points and snapshots,” says Siansky. “Our response time is at least as good as the NAS devices we were using previously, and the iSCSI system seems to be getting faster as it grows.”
Gilbert Randolph’s transition from NAS to an iSCSI SAN has increased uptime and allowed Siansky to build out a virtual-server infrastructure. -KK
Amerex Brokers: FC + iSCSI
Amerex Brokers LLC, a division of GFI Group, specializes in energy markets, including electrical power, natural gas, emission allowances and renewable energy credits, as well as providing energy procurement services.
Brian Trudeau, Amerex Brokers’ CIO, has a variety of storage requirements for supporting 100 brokers in a variety of locations. Trudeau has a hybrid infrastructure consisting of Fibre Channel and iSCSI storage from Compellent to meet his production and disaster-recovery needs.
Amerex has a 10TB SAN at its primary site with a mix of Fibre Channel and iSCSI, while the company’s disaster-recovery site has approximately 6TB of capacity and is strictly iSCSI.
“We went with iSCSI for a couple of reasons. The first was that it was a requirement by Compellent for replication. The second was for connecting our legacy servers that don’t require a lot of bandwidth,” says Trudeau. “It was a cheap alternative to Fibre Channel for migrating LUNs or data from old servers on to the SAN.
“iSCSI is cheaper than buying Fibre Channel cards and allows for connectivity using free iSCSI software initiators,” says Trudeau. But, he isn’t ready to throw all of his application storage on iSCSI. “There are performance issues. If I were trying to run SQL Server or Exchange, which is my primary mechanism for communication, I wouldn’t necessarily use iSCSI,” he says.
But Trudeau has high hopes for the future of iSCSI, regardless of whether Amerex Brokers expands its usage of the technology. “When it becomes prevalent, 10Gbps Ethernet might upset the balance in favor of iSCSI, but right now it’s good to have the competition between the Fibre Channel and iSCSI camps. It keeps the vendors pushing the performance envelope,” says Trudeau.
The cornerstone of Trudeau’s SAN is Compellent’s Storage Center hardware and software, which is based on a Dynamic Block Architecture to enable data movement and access at the block level. The Storage Center hardware architecture is designed with clustered controllers for no single point of failure. The Storage Center software suite includes automated remote replication, storage tiering, thin provisioning, continuous snapshots, and disk-level storage virtualization capabilities.
Trudeau says that despite the hands-off nature of iSCSI and its simple management, there are some areas for improvement-namely, bandwidth utilization. “We didn’t run into any ‘gotchas’ other than dealing with replication over a WAN link and TCP window size, and not being able to completely take advantage of the size of our pipe between our two sites in Houston and Sugarland,” says Trudeau. “We want to really push the replication harder and get it up to 100Mbps, but it still works really well.” -KK
HMC: iSCSI + NAS gateway
In evaluating its SAN options, Claremont, CA-based Harvey Mudd College (HMC)-a math, science and engineering school-first looked at Fibre Channel but, as usual for smaller organizations, the school was put off by both the initial capital costs as well as the per-gigabyte pricing of some of the larger vendors.
“Everything favors iSCSI in the long run, and with the emergence of 10Gbps Ethernet we have enough headroom to scale,” says Andy Davenport, systems and networks group leader at HMC.
The college installed a model 9240 Unified Storage Gateway from Reldata, which supports iSCSI SANs, NAS (CIFS and NFS), and WAN replication. At HMC, the 9240 gateway is configured with dual active-active controllers in a fail-over setup. The system also includes four Gigabit Ethernet ports (the 9240 can also be configured with a 10Gbps Ethernet port), the RELvos 2.1 operating system, 10Gbps Ethernet connectivity, SAS disk drives, and backup and replication software.
Reldata’s systems allow users to connect third-party disk subsystems. HMC, for example, added disks and a JBOD array it already had to boost capacity. In a Reldata SAN, all of the storage appears as a single, virtualized storage pool. -DS
Beeville: Ease of use
Like many small organizations, schools face a number of challenges when it comes to storing and protecting critical data. The catch is that school systems must meet many of the same compliance and litigation requirements as other entities, yet with tighter budget restrictions.
In his role as technology director for the Beeville Independent School District (ISD), in Beeville, TX, Lawrence Garcia maintains and optimizes the district’s network.
In 2006, the Beeville ISD made the decision to move from a hodgepodge of labor-intensive backups to a centralized, networked storage system. Garcia and his team of three technicians were backing up and restoring home directories for more than 500 users across seven campuses using DAS and USB thumb drives. The process was cumbersome and often meant long restore times of up to half a day.
Recognizing that Beeville ISD needed a faster, more-secure and user-friendly storage architecture, Garcia began visiting his peers in local school districts to see how other educational institutions were meeting their storage needs. Key factors included reliability, ease of use, and low cost.
“We didn’t want to invest in the hardware required for Fibre Channel. Ease of use was also a concern, and iSCSI was easier to manage,” says Garcia.
The Beeville ISD evaluated products from Dell, EMC, and Xiotech, ultimately opting for Xiotech’s Magnitude 3D 3000e storage system. The 3D 3000e is Xiotech’s entry-level SAN array, and has a maximum capacity of 84TB, replication, snapshots, virtualization, and the ability to simultaneously attach to both Fibre Channel and IP SANs.
Garcia’s implementation is a modest one: The Xiotech array only has about 5TB of capacity. The Magnitude 3D 3000e serves as a centralized backup repository for each of Beeville ISD’s seven campuses. Garcia plans to expand his iSCSI SAN with another 2.5TB this year. -KK
Oxford University: Consolidation
Oxford University’s Faculty of Mediaeval and Modern Languages is one of the largest in the UK, and together with the Linguistics faculty it employs a staff of nearly 250 in support of more than 100 post-graduate students.
To protect their data, every night the IT team was backing up data from multiple servers to DAS. The legacy servers and DAS infrastructure were dated and prompted the team to deploy a networked storage system to support its NetWare and Linux servers.
Interoperability with legacy systems was the top concern and, as it turns out, not as easy a requirement to meet as one might think. “We were looking for a storage solution that would interoperate with NetWare,” says Jon Edwards, IT officer at Oxford. “A lot of the systems out there now are NAS boxes and are really more suitable for Windows environments.”
Not surprisingly, the cost of bringing in a new storage system was a major consideration, but the concern went beyond the initial price tag. Edwards was more concerned with ongoing operating costs. “Many people think of cost as dollars, but it’s more the cost of personnel time that concerned us,” says Edwards.
After considering a number of products, Edwards chose storage management software from start-up StorMagic. The IT team deployed the software to manage a 12-bay RAID system populated with six 500GB SATA drives for a total capacity of 3TB in a RAID-6 configuration.
StorMagic’s SM Series iSCSI software includes features such as data migration, snapshots, and consolidation, allowing users to share, manage, and protect data even with limited IT resources and no storage expertise. The StorMagic software consolidates storage volumes into a single pool to simplify capacity management and allocation and enables users to monitor and balance physical storage.
All file storage for the two faculties at Oxford has since been moved onto a single RAID system managed by StorMagic software. Now the IT team can allocate, consolidate, and grow storage volumes with just a few clicks, ensuring users benefit from the most appropriate levels of storage capacity, performance, and data protection.
Edwards says the benefits of having a centralized, networked iSCSI infrastructure are numerous, the most notable of which is ease of management. “The ability to divvy up our storage into discrete blocks and expand or contract those blocks when necessary is important,” he says. Next up: implementation of virtualization. -KK
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