EMC Storage Product Knowledge Sharing

VMware hosts require few mandatory FA bits setting before SAN storage to be provision. Apart from FA bits a series of procedure require from installing HBAs, HBA Firmware and drivers, zoning, mapping, masking devices, to configure kernel files and devices.

Let’s assume we have already identified Symmetrix FA port for VMware host and completed zoning on switch. It is better to have separate FA pair for VMware host. (You can connect VMware host to 2 pair FA if you have enough FA resources available and going to deploy critical application which require more performance).

In the current storage markets and technology, storage tiers are defined by availability, functionality, performance and costs. In fact data can move up and down tiers as time and business required.

Tier "0" is not new in storage market but for implementation purposes it has been difficult to accommodate because it requires best performance and lowest latency. Enterprise Flash disks (Solid State Disks) capable to meet this requirement. It is possible to get more performance for company most critical applications. The performance can be gained through using Flash drives supported in VMAX and DMX-4 systems. One Flash drive can deliver IOPS equivalent to 30 15K RPM hard disk drives with approximately 1 ms application response time. Flash memory achieves performance and the lowest latency ever available in the enterprise class storage array.

Tier “0” application can be closely coupled with other storage tier within Symetrix series for consistency and efficiency, reducing cost of company for manual data layout or data migration from old disk to new high speed disk.

Tier “0” storage can be used to accelerate online transaction processing, accelerating performance with large indices and frequently accessed database tables i.e. Oracle, DB2 databases and SAP R/3. Tier 0 can also improve performance in batch processing and shorten batch processing in windows environments.

Tier “0” storage performance will help application that needs the lowest latency and response time possible. The following applications can get benefited through using Tier 0 storage:

- Algorithmic trading
- Data modeling
- Trade optimization
- Realtime data/feed processing
- Contextual web advertising
- Other realtime transaction systems
- Currency exchange and arbitrage

Tier “0” storage is most beneficial with random read miss application. If random read miss percentage is low, application will not see any performance difference since writes and sequential reads/writes already leverage Symmetrix cache to achieve the lowest possible response time.

For example, if the read hit percentage is high >90 % as compared to read misses, such application like DSS, Streaming media, improvements provided by Tier 0 storage will not likely be enough to be cost-effective.

Think when you are creating a point-in-time image for multiple devices. It is easy to create a point-in-time image of entire set of logical device at same time. In order achieve this you need to shut down an application so that no IO will occurs while you creating a point-in-time image. This is big problem in today’s environment where every company looking solution for zero down time.
The EMC provided solution to this problem is called “Enginuity Consistency Assist”. When you create a set of sessions and invoke Enginuity Consistency Assist, the Symmetrix aligns the I/O of those devices and halts all I/O from the host systems very briefly—much faster than the applications can detect—while it creates the session. It then resumes normal operation without any application impact.
TimeFinder Consistent Split using (TimeFinder/Consistency Groups) allows the splitting off of a consistent, re-startable image of an Oracle database instance within seconds with no interruption to the online Oracle database instance.
Ÿ - Allows users to split off a dependent write consistent, re-startable image of application without interrupting online services
Ÿ - Using TimeFinder/Consistency Groups to defer write I/O at the Symmetrix before a split
Ÿ - Consistent split can be performed by any host running Solutions Enabler connected to the Symmetrix
Ÿ - Tested and available including HP-UX, Solaris, AIX, Linux, and Windows
Ÿ - No database shutdown or requirement to have database put into backup mode (Oracle).

Using TF/CG, consistent splits helps to avoid inconsistencies and restart problems that can occur with using Oracle hot-backup mode (not quiescing the database).

The major benefits of TF/CG are:
• No disruption to the online Oracle database to obtain a Point-in-Time image
• Provides a consistent, re-startable image of the Oracle database for testing new versions or database patch updates before deploying for use in production environments
• Can be used to obtain a business point of consistency for business restart requirements for which Oracle has been identified as one of multiple databases for such an environment.

The same benefits apply using TF/CG in a clustered environment as in a non-clustered environment:
- No disruption to the online Oracle database to obtain a Point-in-Time image in a Oracle single instance environment or when using Oracle Real Application Clusters
- Provides a consistent, re-startable image of the Oracle database for testing new versions or database patch updates before deploying for use in clustered production environments
- Can be used to obtain a business point of consistency for business restart requirements for which Oracle has been identified as one of multiple databases for such an environment.