Legal: © Wikibon 2008. This document is copyright protected by Wikibon and does not fall under the GNU general license terms for Wikibon.org. Links to this article from external sources are allowed, however any other re-distribution of this content for commercial purposes is strictly prohibited. Please contact Wikibon for more information.

The case cited herein in was quoted by EMC in a recent press release on Invista 2.0. Wikibon independently followed up and interviewed Jon Miller of Purdue University (Purdue). Wikibon case studies are developed independently and their development is not initiated for or funded by any single company. Wikibon reports actual customer experiences and results with no attempt to emphasize any one vendor’s strengths or weaknesses. Read the full disclaimer.

Highlights

Wikibon was initially skeptical when EMC cited Purdue as a key reference for Invista 2.0. Several members indicated that a university environment was not the classic reference model for mission critical business applications. While generally that is true, we found the environment at Purdue to represent the type of diversity and complexity that virtualization engines are designed to address. We feel the situation at Purdue represents a typical for-profit company in industries such as wholesale distribution, retail, light manufacturing, etc. Moreover, Purdue IT management are astute and in our view are applying several best practices in storage virtualization.

Purdue University in West Lafayette, Indiana fundamentally has three IT support initiatives:

1. IT support for Research
2. IT support for teaching and learning
3. IT support for business applications

IT support for Research is decentralized, with only shared networks centralized. The IT support for teaching and business applications are centralized, and there is closer alignment in approach. The business applications supported include normal university applications providing services to student and faculty.

Eighteen months ago, storage management was “out of control”, according to Jon Miller, storage administrator at Purdue. Utilization was very low and most of the SAN based storage was not appropriately tiered and being managed by the application staff. There were fourteen separate SAN switches and a lack of continuity in Storage Management which led to a fragmented design and poor administration of resources. The SAN fabric was of a mesh design, and switch ports were consumed in multiple interswitch links (ISLs). To bring this under control, the SAN fabric was redesigned into a Core/Edge topology, with two Brocade director class switches implemented at the core. Appropriate tiering was implemented on mainly EMC DMX and CLARiiON arrays, file services were centralized on EMC Celerra, and archiving managed on EMC Centera.

This helped significantly, but the IT department still found it difficult to optimize the allocation and management of storage on the SAN. Once storage was allocated, it was extremely time-consuming to add capacity and move it. It required significant planning and the help and cooperation of the platform administration groups to achieve any change.

The Purdue IT department decided that the next stage of storage infrastructure improvement was to virtualize the storage environment. This would allow storage to be migrated seamlessly without impacting the users, would allow the management of storage to be centralized, and would allow lower cost storage arrays and storage management software to be used.

The Purdue IT department looked at virtualization offerings from EMC, Hitachi and IBM, and choose an EMC Invista from its incumbent supplier as the least disruptive and lowest risk option. The Invista is planned to support all SAN arrays except email Exchange and backup. It is in an early stage of deployment and will be fully deployed over the next six months.

Current Storage Snapshot

The SAN consists of a little over 200 terabytes of storage. Tier-one storage is on two EMC DMX-3 arrays (36TB) which support the ERP and VISTA/WebCT applications in particular. The DMX-3 arrays are part of the package and data from the replaced DMX-2 arrays is being migrated using Invista. There are about five CLARiiON arrays (135 TB), one Sun array (25TB), and two Centera arrays (9TB). The servers attached to the SAN include about 30 Windows and 70 UNIX servers, supporting native machines and about 200 VMware machines. The two SAN Brocade Director switches and fourteen Brocade Departmental switches support 640 ports. There is no storage chargeback system in place.

The applications supported by the SAN include Email, Financial, Educational applications (e.g., Blackboard VISTA), HR, Housing & Food Services, Physical Facilities, Student Support Systems, Alumni Development, and other University Systems. The main database systems supported on the SAN are Oracle 9i and Oracle 10g. The main ERP system is SAP. More details at the Purdue University website.

Pain Points

• The cost of EMC DMX storage is significantly higher than EMC modular storage
• Migration of storage from array to array takes planning and involvement of platform and applications groups to execute. It is very difficult to achieve and requires an extensive amount of time (months) to complete
• Although there has been improvement since the SAN reorganization, there is still low storage utilization and a user perception of inflexibility in IT storage allocation.
• SRDF on the Symmetrix arrays requires multiple copies of data and expensive software. It is overkill for many of the applications that use it, and many of the databases and systems now have lower cost alternatives for remote replication.

Solution Strategy

After evaluating several products, Purdue chose Invista to implement its storage virtualization strategy. The organization acquired two Invista appliances providing mutual backup for control and metadata regarding where the data is stored. All SAN block-based storage (with the exception of the email Exchange system and the backup systems) are planned to be positioned behind Invista, including tier-one DMX-3’s. Purdue is investigating upgrading the two Brocade Core switches with a special blade to enhance performance if needed. In this case, Invista will operate with intelligent switches (Brocade 7420’s) ISL’d to the core. The “intelligent blades” will eliminate the 16 ISL’s to the core and improve bandwidth. Most of the current storage management software from the DMX and CLARiiON is being retained, allowing the least change to existing application and storage management procedures. Business continuance procedures that use EMC’s Symmetrix based SRDF are being modified to use either native Oracle 9i or 10G database support for remote replication or Invista based remote replication solutions.

Adoption Issues

Moving responsibility for storage allocation, performance and reliability from the platform and applications groups to the IT storage group could take a considerable amount of time to implement and require senior IT management support. As Jon Miller says “It will take time for the concept of ‘virtualized storage’ to take hold. Platform groups have been ‘array centric’ and will not be comfortable with the idea of storage administration ‘moving things around’."

Purdue’s storage group must establish a track record of efficiency, responsiveness and competency so that platform, application and user groups are confident that storage provisioned meets requirements. Similarly, the storage group must ensure user satisfaction with business continuance after any move from SRDF to Invista-based remote replication or other solutions.

Finally, if Purdue chooses to add additional blades in the Brocade switches, significant additional testing and integration will be required. Notably this upgrade will require Purdue to migrate to from Invista 2.0 to Invista 2.1 and it is unclear to Purdue how EMC plans to support migration non-disruptively.

Editor's Note: In late January, 2008, Wikibon had a follow up conversation with EMC representatives to understand how EMC plans to support the 2.0-->2.1 migration non-disruptively. The following points are relevant:

1. EMC confirms that the Invista architecture supports non-disruptive migrations from Invista 2.0 to Invista 2.1 for installations with a dual fabric;
2. The approach customers should take is to take down one half of the fabric, do the upgrade, failover and do the upgrade on the other half;
3. While customers should coordinate with SAN management staff and other related elements to prepare for the upgrade, Invista uses a non-disruptive upgrade wizard to step through the migration process. The timescale for the Invista piece of the upgrade is measured in hours. The entire process for components outside of Invista will be dependent upon complexity of installation, scale, types of devices attached, customer change management process requirements, etc.

Wikibon believes EMC understands the imperative of non-disruptive upgrades to Invista and will support the requirement effectively, although because it's early in the Invista adoption cycle, users should exercise caution with respect to this capability, understand the migration path clearly and secure guarantees from EMC that it will be done non-disruptively.

Benefits

A major benefit of the project is Purdue plans to reduce expenditures by using more, lower-cost CLARiiON tier-two storage arrays. As well, Purdue plans to migrate most open systems usage of SRDF to the remote replication capabilities of Invista, and cut both software licensing/maintenance costs and the amount of storage required to support business continuance.

It has also begun to reduce dramatically the number of people who are aware of changes to storage, especially where migrations are involved. Thusfar, Purdue has seen advantages in terms of the storage group being more responsive and less of an obstacle.

In addition, Purdue plans to achieve much higher utilization of its SAN connected storage assets at a much reduced cost, and use this success to reduce the amount of storage consumed. Purdue also hopes to avoid increased staff to manage platforms and storage as a result of the project.

Best Practices

Based on this project, Purdue advises the following to peer organizations:

• Determine the best solution for your business and then fit it economically;
• Be certain the environment is ready for storage virtualization-- watch out for 'weak links' in the infrastructure because you're putting all eggs in a virtualization basket. This includes having a robust enough SAN and enough switch port capacity. As well, ensure that firmware and patches are up to date;
• Develop a migration strategy and get buy in from administration and clients;

And of course...get the best price.

Conclusions

Wikibon draws the following conclusions from this case study: While Purdue was happy with the performance and reliability of tier-one Symmetrix storage, it wanted to use lower cost CLARiiON modular solutions where possible. The university has confidence in EMC as its supplier, and wanted to leverage existing relationships. EMC successfully created a financially attractive offering by packaging up additional Symmetrix boxes with Invista together with deep educational discounts offered by most suppliers. EMC successfully sold the potential scalability of Invista using the split path architecture as a competitive differentiator. Because Purdue's applications do not all require SRDF resilience, recovery can now be satisfied with less expensive methods. The organization is reducing its software costs by utilizing, for example, remote replication with Invista. Virtualization is now ready for general adoption, with EMC joining other established players and upstarts to create significant market momentum. One of biggest benefits of virtualization for Purdue will be the ability to non-disruptively migrate storage with no application downtime and no involvement of platform administration. Wikibon believes that there are three weak points in the strategy:

1. Purdue could make significant additional savings by reducing the number of separate but similar storage management capabilities. This could be done by tightly defining storage tier functionality and rationalizing overlapping functionality (e.g. copy services on Symmetrix, CLARiiON and Invista);
2. Purdue does not have a strong dictate in place to stop users and application administration from utilizing higher performance/function storage rather than using the storage allocated by the storage group. It may take a long time after virtualization is implemented for decisions on allocation of storage tiers to be based on actual user requirements rather than user preference. Senior IT management and Purdue University user management will need to be proactive in driving change;
3. The additional complexity of a fourth component (SAN switch blades) to coordinate firmware changes (along with SAN switch, servers, and storage arrays) is likely to reduce the choice and timeliness of storage, SAN and server upgrade options.

On balance, however, Wikibon concludes Purdue University made a sound business decision in electing to implement Invista from its established supplier, EMC. All the proposed vendor solutions were viable, but the EMC solution was low risk because of the least change required to existing processes and procedures, and familiarity and comfort with how EMC operates. Purdue is implementing a good strategy that, if well executed, will put in place a significantly more cost effective storage infrastructure. It should improve storage utilization and flexibility and should enable storage to be potentially handled more efficiently by storage administration, rather than platform administration.