Why not Exadata

1. Oracle database only. If you want to run other apps such as another web servers, app servers or other databases like SQL Server or DB2, you can’t.
2. 11g or greater only. If you have legacy versions of Oracle you must upgrade in order to run them.
3. RAC only. You have to run RAC, even for a single instance DB, you run RAC with only one active instance. Technically I guess you could have a single node running standalone and not clustered, but I’ve never seen Oracle approve such a configuration
4. Data protection requires ASM to perform mirroring. this means ASM is performing at least 2 or 3 (with double mirroring) writes, so writes are slower. Oracle performance numbers are based on reads.
5. Oracle Flash Cache is read only, so all writes first get written to disk, then updated in cache if the data is in cache.  
6. Not 5 nines availability. Data is mirrored across storage cells using ASM. If a storage node crashes and you are only using standard mirroring then you have 12 drives offline until the cell is repaired or restarted. That can be risky. Furthermore, when applying a patch each cell is brought offline for patching, making you vulnerable to a double outage. Patching can easily take up to 30 minutes per cell assuming no errors occur. If an error occurs the outage could be even longer. Furthermore, if a cell is lost all 12 drives need to be reprotected which could take many hours or even days to rebuild, depending on the drive type and amount of data stored. Your options are to create a second mirrors (double mirroring) which is very costly or leverage Dataguard which would require you to fail over to your DR site.
7. No raid 5,6 or 10 options. Since mirroring is your only option it can be very expensive. Oracle’s response is usually to emphasize you can use columnar compression for increased compression ratios, but columnar data stores are only applicable to warehousing and analytic workloads, and don’t lend themselves to transactional work loads.
8. Dataguard is the only option for replication.
9. RMan is the only option for backing up.
10. No Hardware options for snapshots or clones.
11. SQL offloading, the magic sauce of Exadata, is only applicable to data warehousing and analytic style queries. Most OLTP/transactional workloads don’t benefit from it, so you won’t see the exponential gains in performance.
12. A single full rack is limited to 168 drives (12 drives per storage cell, and 14 cells in a full rack)
13. The ratio of drives to cores in a storage cell is 1-1. Oracle touts this as a feature, but in reality, a single core can drive a lot more than a single drive, which is a waste of money. They need the drive ratio for SQL offloading, but as already mentioned, there are limited workloads that actually perform SQL offloading.
14. It’s an Oracle only solution, locking you into to just their supported products, software and vision.

Why Vblock

1. Like Exadata, it’s a Pre built, Pre configured, Fully integrated and Certified offering, with a single 1-800 number to call for service.
2. Unlike Exadata, you aren’t limited to what applications you run, including; Oracle Database, Oracle Weblogic, other Oracle apps, as well as non Oracle apps such as Websphere, Tomcat, Apache, MS Exchange, MS Sharepoint, Windows, Linux, and other software.
3. Vblock is a full 5 nines solution, offering the industries leading storage, networking and compute tiers to ensure you the highest levels of availability and data protection and security.
4. Run any version of Oracle database, not just 11g.
5. Run RAC or non RAC single instance databases.
6. Mix and match virtualization on some nodes and physical on other nodes, giving you the best of both worlds. If you aren’t comfortable virtualizing Oracle in production, but are willing to Virtualize everything else, why have two different environments. On Vblock you can do both from a single platform.
7. With an EMC VNX or VMAX storage array powering the Vblock, you aren’t limited to just mirroring. You can choose Raid 0,1,5,6 and 10 configuration. Choose what’s right for you, and even mix and match across different drives.
8. Leverage EMC FAST VP and FAST Cache to enable automatic storage tiering of your data across Enterprise Flash Drives, SAS/FC and NL-SAS/SATA. The intelligence behind FAST will dynamically move data based on real usage patterns, not based on date ranges or convoluted business logic. It’s the best way in the industry to optimize performance while minimizing cost, and it’s all automatic.
9. Provides writeable flash storage in both persistent and cache modes, achieving improved write performance and efficiencies.
10. Leverage best of breed replication solutions such as SRDF, Recoverpoint, or Dataguard. With SRDF and Recoverpoint you aren’t limited to just the database files, so you can use a single replication strategy for all your DR needs.
11. Choose from best of breed backup options, including Avamar, Data Domain or RMan. Choose what’s right for your business and don’t be locked in to a single choice.
12. Leverage HW snaps and clones to provide the highest efficiencies of offloading storage tasks to the storage array where they run best. Also the use of snaps stores only the delta changes further saving disk space.
13. Vblock has similar performance features to Exadata, including Enterprise Flash Drives, Westmere Processors, 10 GbE Ethernet (load balanced across 4 per node for 40 GbE throughput). Runs Oracle 11g, and supports 11g advanced features such as Advanced Compression. Coupled with EMC’s FAST and Power Path to optimize storage tiering you have an extremely fast and balanced configuration.
14. When SQL offloading is required for special data warehousing and analytics, look at Greenplum as an alternative. Greenplum’s Chorus is a virtual node that can run within the Vblock, or you can use Hadoop to automate the aggregation and streaming of data out of your OLTP database on Vblock into a Greenplum appliance.
15. Scale a single Vblock 700 to nearly 2000 drives.
16. Vblock is a best of breed solution, developed by a coalition that includes VMware, Cisco, EMC and Intel. All four companies are leaders in their respective space and provide the only best of breed solution as a single integrated and supported product, not just a reference architecture.
    
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