IP SAN

Storing it the IP way

L&T Hazira's Heavy Engineering Division chose IP over Fibre Channel for its SAN to save costs and to utilise the IP skills of its IT staff.
by Soutiman Das Gupta

L&T's Heavy Engineering Division (HED) in Hazira (Gujarat) needed to evolve its DAS environment and build an infrastructure that offered better data discipline, security, and capacity. A SAN was an obvious choice and L&T HED took that route. However, it chose to go with IP instead of Fibre Channel (FC). The IP SAN solution provides high data availability, reliability, security, and doesn't need extra technical manpower resources, since the existing workforce is familiar with IP.

Heavy business at HED

The IT team of L&T’s HED in Hazira. V A Khargonkar, Assistant General Manager, IT in the centre

Located 300 km north of Mumbai, L&T's HED is involved with the design and manufacture of hi-tech custom built fabricated equipment for core sector industries such as oil & gas, refineries, petrochemicals, and fertilisers.

The division comprises eight Strategic Business Units (SBUs) and six nationwide manufacturing plants located in different parts of the country.

The Hazira campus is spread over 2.5 sq. km and the Gigabit LAN runs on a Cisco Layer 3 switched backbone. The infrastructure offers services such as Baan ERP, intranet, e-mail, Web, and file & print to around 500 workstations.

The DAS days

The organisation used a number of Intel and Sun servers and relied on DAS to fulfil its information storage needs. For a while, DAS proved to be a cost effective and adequate storage solution to support various enterprise applications. DAS devices such as DLT and DAT drives were physically connected to the host servers through a SCSI cable, and performed periodic backup and restore functions. Over time, the limitations of DAS began to surface.

In a typical DAS environment, each storage device is connected to a single server and the storage can only be viewed and accessed through the OS of the attached server. "As a result, when there are multiple storage and server pairs it becomes increasingly difficult for the IT staff to manage and track data on each individual server," explained V A Khargonkar, Assistant General Manager, IT of the company.

The DAS environment needed considerable time and effort for backup and restoration. Each DAS island required that data be streamed across the network to the backup or restore systems, which lead to heavy network utilisation. In the past, this was not an issue due to a big backup window, but as business expanded, this became a problem.

Networked storage and IP

"We wanted to introduce data discipline and security in the storage infrastructure, and wanted to consolidate the architecture. So we decided to invest in a centralised storage solution," says Khargonkar.

After the decision to use networked storage, the company looked at several options—NAS servers, FC SANs, and IP SANs. It decided to go with an IP SAN as it wanted the benefits of a SAN along with the cost-effectiveness and easy manageability of IP. This was especially relevant because the existing IT workforce was already well versed in IP.

After evaluating a number of storage vendors, the company decided to purchase IP SAN solutions from Intransa.

"A key criterion for choosing the IP SAN solution was the need of a storage solution that made use of existing skill sets. We were delighted to find, during the pilot phase, that the IP SAN solution could be implemented and managed with no major retraining of our staff. This certainly made a big difference," explained Khargonkar.

The IP SAN at L&T Hazira

L&T Hazira deployed Intransa IP5000, which is a modular, IP-based block-storage SAN array with 4 to 24 TB of raw capacity. It consists of a storage controller module and a disk enclosure, which centralises storage devices to make them available across a network.

superior utilisation at a lower cost

"We were finally able to manage our growing storage resources and deliver high data availability across the enterprise network. All this at significantly lower cost per MB of data stored," said Khargonkar.

The solution delivers superior resource utilisation by reducing the need to purchase individual servers to increase storage needs.

"If we need to add more storage capacity, all we have to do is mount a new disk enclosure in the rack and plug the Ethernet cable to the Gigabit Ethernet switch," explained Khargonkar. The IP5000 storage controller will automatically recognise the new disks and make free space available to provision and host servers.

Khargonkar said, "The solution also dramatically improves the efficiency of the spare storage capacity by creating a global spare for all the disks in the system so that when a failure occurs, the IP5000 will automatically put the spare to use."

The iSCSI-based solution also simplifies clustering and management of the storage system with a StorControl management tool that lets systems administrators manage and monitor the entire IP5000 system, automate tasks, and even assign individual volumes.

Administrators can increase storage capacity 'on the fly' with a simple 'drag and drop' function of the volume bar. This resource allocation dramatically simplifies how the company plans and allocates its storage capacity, dynamically assigns unused capacity to servers during times of high demand, and reallocates that same space when it is no longer needed.

The company currently uses around 35 percent of the IP SAN's capacity.

Backups become simpler

With the help of the IP SAN architecture, the company created a centralised pool of storage to ease its backup and restore methods and reduce completion time. Backups are now run directly on the back-end storage network rather than the user-facing front-end. An incremental backup of all the servers can be bypassed by leveraging Intransa's Snapshot technology.

The previous DAS configuration required tape cartridges to be physically changed on each server. The IP SAN enables the continuously growing backup log files to be kept online. This facilitates the rapid identification of archived data for restoration. Data can be restored from disk by mounting a snapshot volume.

A snapshot home directory has been created so that users can complete restoration on their own. This reduces help desk requests freeing IT technicians to spend their time on other projects.

Overcoming issues

The company faced a number of technology and administrative challenges when it built its storage infrastructure. There were some problems in the installation of clusters, and in printer management.

The workforce was used to storing their data on DAS devices. It was a challenge to convince them to store the business-critical information on the centralised system. Users also had to be trained to log into the storage domain instead of the NDS.

"Although we had to face these challenges in the beginning, we were able to find effective workarounds," said Khargonkar.

He created a storage policy document and manages the storage infrastructure according to it. The policy contains information on data retention, security, and usage.

On the anvil

Till now, L&T Hazira has performed consolidation of the enterprise's information, which includes files and drawings. In the next phase, the organisation will look at storage systems for its Informix database. The company also plans to implement a box-to-box mirroring solution for disaster recovery.

Soutiman Das Gupta can be reached at soutimand@networkmagazineindia.com