3) Virtual Provisioning Phase 2 - Support for MirrorView and SAN Copy replication on thin LUNs has been added.
What is “Tier 0” in Storage Environments?
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. Read More →
3) Virtual Provisioning Phase 2 - Support for MirrorView and SAN Copy replication on thin LUNs has been added.
PowerPath Migrator Enabler is a host-base migration tools from EMC that allows you to migrate data between storage systems with little or no interruption to data access. This tool can be use in conjunction with other underlying technology such as EMC Invista, Open Replicator. PPME use the PowerPath filter dirvers to provide non-disruptive or minimally disruptive migrations. Only specific host plateforms are supported by PPME. Please check EMC support matrix for supported host systems. One of the PPME features that supports pseduo-to-pseduo, native-to-native and native-to-pseudo device migration.
Consider the following when designing and configuring PPME:
Ø Remote devices do not have to be the same RAID type or meta-configuration.
Ø Target devices must be the same size or large than the source control device.
Ø Target directors act as initiators in the SAN.
Ø Contrary to the recommendations for Open Replicator, the source device remains online during the “hot pull.”
Ø The two storage systems involved in the migration must be connected directly or through a switch, and they must be able to communicate.
Ø Every port on the target array that allows access to the target device must also have access to the source device through at least one port on the source array. This can be counter to some established zoning policies.
Ø Since PPME with Open Replicator uses FA resources, determine whether this utility will be used in a production environment. In addition, consider FA bandwidth assessments so that appropriate throttling parameters (that is, pace or ceiling).
Ø The powermig throttle parameter sets the pace of an individual migration by using the pace parameter of Open Replicator:
Ø Faster (lower throttle) makes the migration faster, but may impact application I/O performance.
Ø Slower (higher throttle) makes the migration slower.
Ø The default is five (midpoint).
Ø When setting a ceiling to limit for Open Replicator throughput for a director/port:
Ø The ceiling value is set as a percentage of a director/port’s total capacity.
Ø The ceiling can be set for a given director, port, director and port, or all director and ports in the Symmetrix array.
Ø To set ceiling values, you must use symrcopy set ceiling directly (powermig does not provide a way to do this)
Ø Once the hot pull has completed, remove or re-use the source device.
Ø Do not forget to “clean up” the zoning once you have completed migration activities.
Hope this will be useful in migration planning or selecting migration tools. I will try to explain in deatil in coming post such as PPME with Open Replicator, Solution Enabler etc..
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.
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.
- Allows users to split off a dependent write consistent, re-startable image of application without interrupting online services
- Using TimeFinder/Consistency Groups to defer write I/O at the Symmetrix before a split
- Consistent split can be performed by any host running Solutions Enabler connected to the Symmetrix
- Tested and available including HP-UX, Solaris, AIX, Linux, and Windows
- 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).
• 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.
Auto-provisioning requires Enginuity 5874 or later. It simplify Symmetrix provisioning by allowing you to create group of devices like storage group in CLARiiON, Front-End Port Group and Host Initiators Group and then associate these groups with each other in a masking view.
The following are the basic steps for provisioning Symmetrix using Auto-Provisioning:-
1) Create a Storage Group
2) Create a Port Group
3) Create an Initiator Group
4) Associate the groups in a Masking View.
Creating Storage Group:- It is component of Auto-Provisioning group and FAST ( Will discuss about FAST in later post), both require Enginiuity 5874. The maximum number of storage group allowed per array is 8192. A storage group can contain up to 4096 devices. A Symmetrix device can belong to more than one storage group.
Note:- By default Dynamic LUN addresses will assigned to each device. If can manually assign the host LUN addresses for the device you are adding to the group by clicking Set LUN Address- Storage group dialog box.
Creating Port Group:- A port can belong to more than one port group and port must have the ACLX bit enabled. For example if you want FA 5A and 12 A for windows operating system, you can create port group name called WIN_PortGrp or Win_FA5A_FA12A_PrtGrp etc.
Creating Initiator Group:- The maximum number of initiator groups allowed per Symmetrix array is 8000. An initiator group can contain up to 32 initiator of any type and contain other initiator groups (cascaded to only one level).
Initiator Group name must be unique from other initiator groups on the array and cannot exceed 64 characters. Initiator group names are case-insensitive.
Creating Masking view:- It just a co-relation between Storage Group, Port Group and Initiator Group and you are done! Device will be mapped automatically to selected port group and masked to selected initiator groups.
About Me
- Diwakar
- Sr. Solutions Architect; Expertise: - Cloud Design & Architect - Data Center Consolidation - DC/Storage Virtualization - Technology Refresh - Data Migration - SAN Refresh - Data Center Architecture More info:- diwakar@emcstorageinfo.com