Snapshot on a page
CS3 is a US retail organization that is centralizing its computing operations, and closing down one of its city data centers. EMC is a major supplier to CS3 for storage and VMware, and was chosen to manage the storage portion of the data center migration.
The current storage is mainly direct attach to about 500 servers. There are three Brocade SAN networks connecting EMC DMX and CLARiiON arrays. In addition CS3 is using EMC Centera for archiving and EMC Celerra for NAS. There is no chargeback system in place, and applications owners have little incentive to optimize storage costs. Overall costs of DMX storage are 2-3 times the costs of CLARiiON and Centera.
The CTO announced a strategy to reduce the cost of storage by moving as much as possible from DMX arrays to tier 2 storage on CLARiiON or Celerra. The centralization exercise was seen as an opportunity to introduce change that would achieve storage cost reduction. Central to this was a new storage virtualization strategy that would allow better utilization of storage and more appropriate dynamic allocation of storage at the beginning and throughout the life of applications.
A key requirement of the solution was that it could be implemented quickly as part of the storage migration initiative that had been outsourced to EMC services. The solution recommended by EMC and agreed by CS3 is to use Invista as an external virtualization appliance and place the EMC DMX and CLARiiON arrays behind it as part of a single SAN fabric. The expectations are that this will allow the storage group to implement a tier 2 default strategy, increase the utilization of storage, eliminate growth in DMX storage and support the disaster recovery VMware environment. Long-term it is expected the storage requirements for new servers and existing servers with directly attached storage would be handled on the SAN.
Current Storage Snapshot
Some 120TB of EMC Symmetrix and EMC CLARiiON are spread over two sites, and connected to about 70 open system servers by three different SANs. The two sites are within 50 miles of each other, one in the city that supports mainly development, and one out of town that support production. There are 800 smaller servers have direct attached storage. There is a third site that will be used for disaster recover is over 500 miles away.
- The cost of EMC DMX storage is 3 or more times higher that EMC modular storage
- Migration of storage from array to array takes enormous planning and is practically impossible to achieve
- The available storage is either directly attached or not accessible, leading to very low
- There are no organizational or financial incentives to persuade users to optimize on storage
- The majority of servers still have directly attached storage, which contributes to inflexibility in storage management
- Any initiative must be implemented as part of the data center moves or it will not happen
- CS3 is moving development work from its city data center to its production data center and closing down the city center
- CS3 is an EMC storage customer, and chose EMC to manage the data migration
- CS3 has mandated that a tiered storage system be implemented as part of the migration. The default storage was to be CLARiiON modular storage. Applications could be migrated to DMX storage only as an exception.
- EMC recommended Invista as the virtualization and tiered storage solution, and CS3 accepted the recommendation.
- CS3 will use EVA and CLARiiON storage with SATA drives for tier 3 storage.
- The number of SANs will be reduced from three to one, and will allow servers access to all tiers. The Brocade fabric will be updated with the necessary blades
- EMC recommended and CS3 accepted that the current storage-based management software in the DMX and CLARiiON are retained. The only Invista software is virtualization software.
- CS3 were training and putting in place a storage group to centrally handle all storage allocations
- Completing the migration of the data center by the end of lease deadline
- Creating a central group to determine what tier data should reside on and migrated to, and relying less on user input.
- Giving this group sufficient authority.
- Ensuring that senior IT management (the CTO) was involved in all exceptions to the CLARiiON default rule.
CS3 plans to save budget by using much cheaper tier 2 storage as the default. CS3 plans to avoid purchasing Symmetrix arrays in the future, and consolidate on it CLARiiON modular storage. CS3 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.
|Vendor Proposal||Advantages for CS3||Drawbacks for CS3||Overall CS3 Assessment|
|EMC Invista||Retail reference using Invista in a similar way, EMC support, speed to adopt, least change to existing procedures||No alternative considered because migration deadlines||***|
Wikibon draws the following conclusions from this case study:
- CS3 has confidence is EMC as its supplier, and outsourced a critical migration project to EMC services.
- EMC has a good retail reference of Invista being used to help data center migration, and will build up references as Invista rolls out
- CS3 and many in the Wikibon community concluded that modular storage and software is sufficient for the vast majority of both mission critical and tier 2 storage.
- CS3 is happy with the performance and reliability of tier 1 Symmetrix storage, but did not believe that the cost differential of two to three times was worth paying for.
- Virtualization is now ready for general adoption, with EMC joining IBM and Hitachi to create significant momentum along with numerous startups including 3PAR and Compellent.
- One of biggest benefits of virtualization for CS3 will be the ability to commission and decommission storage in weeks rather than months. This will reduce the costs of overlapping storage, delays purchase of new storage, and significantly reduces overall storage acquisition costs.
- A tiered storage strategy means that responsibility for the initial and ongoing placement of storage should be centralized, probably as part of the storage administration.
- CS3 asked EMC to undertake the storage and server virtualization projects as part of the overall migration project. CS3 should gain significant benefits from this joint approach.
Wikibon concludes CS3 is implementing a good strategy that, if well executed, will lead to a successful centralization and elimination of a data center, and put in place a significantly more cost effective storage infrastructure. It will improve storage utilization and flexibility. However, there are three weak points in the strategy:
- The lack of an effective charge back mechanism will mean that IT is the only stakeholder with an incentive to reduce storage costs.
- The maintaining of two storage management infrastructures (EMC’s Control Center and Navisphere) will mean high software costs and higher storage administrator costs, and will need to be addressed at a later stage.
- Alternatives to EMC Invista were not evaluated, due to the rapid implementation timescale, which may result in higher storage costs going forward.
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