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Simplifying storage

Deploying a storage area network makes a CIO’s life a lot easier as he can manage his organization’s storage assets with ease. We polled CIOs about their SAN experiences and here’s what they had to say. By Faiz Askari

With Indian enterprises expanding and going global, the amount of data that these organizations need to store, manage and disseminate is growing exponentially. Also there is always a need to better align IT resources including storage resources with an organization’s business needs.

The storage industry in India has seen a paradigm shift in customer requirements from DAS to networked storage and subsequently from SAN and NAS islands to fewer, larger and more manageable consolidated networked storage environments.

SAN enables centralized management and provisioning of storage resources. It streamlines the numbers of IT and storage administrators that an organization needs to deploy.

While sharing some views on SAN’s status among Indian users, Hilal Khan, Head Corporate IT, Honda Motor India Pvt Ltd said, “Mature industries and segments such as BFSI, manufacturing and service provider/telco are the biggest users of SANs. IT/ITES companies deploy SANs mostly in line with their project or client-specific requirements. A lot of government departments are undergoing computerization and automating their processes requiring consolidation of their storage resources in storage area networks.” He pointed out that upcoming segments like retail will also contribute to SAN adoption in due course of time.

Agreeing to a statement which says that, today’s enterprises are information hungry, Vipin Kumar Head of IT Jindal Steel And Power Limited added, “With the ongoing boom in ERP implementation which has lead to application consolidation, not only large enterprises but even SMB organizations are generating quality structured information. There is a growing urge in organizations to not only generate information but to analyze it in great detail. This is resulting in large amounts of data being generated within the enterprise. This has resulted in enterprises looking for large, easily manageable and scalable storage solutions.”

Highlighting the storage demands of today’s enterprise as they are continuously increasing day by day, S C Mittal, ED, (Management Services & IT) at IFFCO, stated, “With liberalization and the opening up of the economy, the Indian enterprise has understood the power of information for [gaining a] competitive edge and survival. With this came the wider need to store information for a longer time—be it structured data, textual data or e-mail communications. The storage of unstructured data is growing at a faster rate than that of structured data as image files demand far more space. In many cases, the data is required to be referred to frequently. With the e-culture becoming prominent, storage for the mailing system is required for a much longer time besides the structured database.”

SAN acceptance

SAN is clearly the most popular technology across verticals with NAS and hybrid storage being deployed in specific environments that require file sharing. Organizations that have adopted network storage technologies like SAN early on, are now consolidating their first generation SAN islands into fewer enterprise-class storage networks.

SAN storage is becoming the de facto industry standard as it is providing high speed, large volume storage which is easily manageable and scalable. SAN storage is being offered by many reputed vendors and therefore getting after-sales support is not an issue. Vipin Kumar said, “With competition setting in, good SAN boxes at various levels namely entry-level, mid-range and the enterprise level are available at competitive prices. The best part about SAN storage is that it allows the CIO to plan for consolidation of various different types of storage currently available in their organizations, thereby minimizing the maintenance and running cost.”

Apart from regular attractions of this technology, there are many other advantages of a SAN system over a normal tape system. Emphasizing such attractions Mittal added, “It has many a times been noticed that in the case of data corruption and restoration, the backup taken does not work. Hence there is a need to take backup onto online media. As data retention and storage demands continue to grow, there is an increasing need for resilient storage infrastructure to support business-on-demand. The need of comprehensive, flexible storage software solution to assist enterprises in addressing their storage management challenges. SAN has become an option for CIOs who are looking for the robust and vast storage networks.

“With SAN in place, varied data from multiple sources can be stored and online analysis can be conducted. Techniques like virtualization and DR site creation for varied types of data has become another helpful asset.”

Acknowledging the potential and acceptance of SAN amongst CIOs, Sumit Mukhija, Business Development Manager, Cisco India & SAARC said, “Storage vendors have highly scalable solutions that enable the consolidation of first generation SAN islands into a fewer number of enterprise-class storage networks. Storage arrays that scale all the way up to 300 TB are not uncommon. From a storage-networking perspective, SAN switches that scale up to 528 ports in a single chassis are now available.”

While commenting on SAN technology’s coverage and acceptability, Khan added, “Since SAN has an image of an easy-to-manage kind of solution, it eases an IT guy’s work. This is the biggest driver behind why SAN has gained a great amount of acceptability from the enterprise community.”

SAN Key Option ahead of CIOs

Applications such as databases, ERP and CRM applications that create and process block data are natural fits for a fiber channel SANs that bring about all the benefits of centralization namely centralized management, provisioning and backups etc. and are key building blocks of an organization’s business continuity policy.

While talking about another key aspect that advocates the adoption of SAN amongst Indian companies deploying enterprise wide applications, Mukhija said, “Another key area that is driving the storage market in India is business continuity and disaster recovery. Most organizations in India are today looking at implementing effective BC/DR policies. Data replication from storage in the primary site to the secondary or DR site is an important aspect of any BD/DR plan and consolidated and networked storage is a pre-requisite for such initiatives.”

Vipin Kumar, added, “In India, SAN is picking up in a big way. A large amount of data generation and mining is being done by enterprises to face competition thereby requiring large, secure and easy-to-manage storage solutions. A SAN provides storage consolidation at an affordable cost, is scalable and there is good post-implementation support. Also with different types of hard disks being available in a single storage box, data backups and restoration can be planned through these boxes in a cost-effective manner rather than the slow approach of using tapes and DATs.”

Managing Storage over a SAN

Today the buzzwords are Utility Computing and Information Lifecycle Management (ILM) and it is not possible to do either without a SAN in place. Khan said, “For us, SAN has proven its worth in terms of manageability. SAN solutions make our life easier as to manage and monitor and get the optimum outcome.”

Giving an example Mittal said, “There might be need for some data to be online and available 24x7. But those e-mails or records will have to be archived on less expensive storage over time.” He also said, “SANs are in the middle of both these trends. If you have to move data based on its applicability and its age, you need SAN. If you need to deploy new applications or provision storage on the fly, you need a SAN. As you can see, SANs are integral components.”

This is where most of the CIOs see intelligence moving into the network. “With intelligence in the network it is possible to keep a mirror copy or a snapshot of the data transparently at line speeds. The Indian market has caught up quickly and a lot of deployment in the area of SANs happens in India,” Mittal said.

SAN is of immediate relevance in large enterprises where there are islands of data and storage. Kumar added, “SAN storage boxes are highly secure, [allow you to store a] good amount of data with redundancy, are easy to manage, scalable and affordable solutions allowing for data and storage consolidation.”

Deployment experience

A SAN is basically an interconnected array of storage devices and host servers. For example, a storage array may connect to a switch through a Fiber Channel (FC) cable, or (in the case of iSCSI) an Ethernet cable. Each host server is equipped with the host bus adapter (HBA) also connects to a switch and switches are typically connected to one another, all forming a fabric of devices.

Today’s SANs use a combination of aggregation and failover techniques to improve their availability and reliability.

Sharing his experience and views about SAN deployment, CIOs have something common to say, which is that SAN storage is easy to deploy. Kumar added, “One needs to check the compatibility of HBA cards to ensure that servers are properly attached to storage. SAN switches along with compatible HBA cards will properly link servers of different makes to a SAN storage box.”

Khan noted, “This is one of the biggest advantages of SAN. It is easy to test and deploy even in a large IT setup. This factor promotes a proactive effort from an IT manager’s standpoint to bring SAN into his IT setup. However, the process involved in actually implementing SAN in any setup is also not that complex.”

However, Khan also added, “In terms of my own experience, I have deployed four SANs in my setup. I have great experience as they were quick to deploy. So deployment has been a good experience so far.”

While giving some technical deployment specifications Mittal said, “Aggregation (sometimes called “trunking”, “link aggregation” or “port aggregation”) is used to combine ports in order to form faster logical communication links between devices. For example, rather than replacing a single 4-port 1 Gbps FC with a 4 Gbps HBA, it may be possible to connect all four ports to a switch, “aggregating” all four existing 1 Gbps ports to form a single logical 4 Gbps path. Of course, this type of aggregation demands more cabling and switched ports, but it offers the benefit of faster performance, load balancing and redundancy. It is often possible to aggregate links between a host server and switch, or between a storage system and a switch, or even between inter-switch links (ISLs).”

Mittal added, “It’s easy to see how multiple physical connections can be combined to improve speed, but the ideas of redundancy/failover and load balancing are all related, and should be explained together. By having multiple physical connections in the same ‘link’, a failure in one HBA port or cable will not cut off the link entirely, and communication can continue at a reduced speed until the failure is repaired. For example, if three 2 Gbps links are aggregated into a single 6 Gbps link, a failure in one of the ports will allow data to continue on the remaining two 2 Gbps links (yielding 4 Gbps). The remaining connections will keep the host server or storage array connected to the SAN—a key premise behind SAN redundancy and high-availability.”

Having deployed SAN in his IT setup, Mittal highlighted another benefit of multiple physical connections is load balancing. He said, “Normally, unrelated physical links can transfer data at independent (and often unpredictable) speeds, and this permits the creation of a bottleneck on one or more of the physical connections that can impact the overall performance of a SAN. Once multiple physical connections are aggregated into a logical data path, data can be distributed equally across the member links to balance the load and ease bottlenecks.” Keep in mind that just because multiple connections may be included in the same link does not automatically mean that all of the connections are carrying data simultaneously.

Challenges

Traditionally, the biggest challenges in terms of storage infrastructure have been distributed storage islands, low utilization levels, lack of flexibility in terms of usage and sharing of resources, application performance etc.

All this mean higher total cost of ownership and storage infrastructure not being aligned to an organization’s business needs. Also, this is not in line with an organization’s need to comply to its own business continuance policies or regulatory requirements.

Having shared all the good experience while having SAN in any organizational setup, Khan gave another perspective, “Although SAN makes life easier for an IT person in terms of managing storage it is not a cost-effective solution. One needs to understand that after all the technology, one has to convince the management. While convincing the management, the CIO or IT head needs to present some clear tangible benefits.” In the case of SAN it becomes difficult to explain tangible benefits. “I think, SAN has to be slightly more cost-effective than what it is right now,” he added.

Giving an example of a typical enterprise environment, Kumar added, “Data from different applications would be stored in different storage platforms like an internal hard disk or any attached array of hard disks. As the number of applications increases, the storage landscape also increases proportionately thereby making it difficult to handle data and storage at different places. This is not only difficult but also requires divergent skills to manage different types of storage. This is where storage consolidation through SAN storage boxes plays a important role. Not only does it consolidate storage, it also helps in bringing the data of various applications on to a common platform.” However, this results in the easier and simpler management of storage and data. Also with redundancy built into these boxes the chances of data loss is minimal.

While highlighting the present status of storage infrastructure, Mittal said, “Till now, the approach has been to invest in servers on which the applications run. These servers are, in turn, attached to storage devices. However, this approach creates islands of data storage. The number of servers and applications running over them reflects the number of storage devices. Managing a scattered DAS is a nightmare for any CIO.”

faiz.askari@expressindia.com