VNX ,, Oracle Redo Logs & Exchange – quick notes!


Replication Manager:

EMC Replication Manager is a software product that enables you to automate and manage EMCs point-in-time replication technologies for EMC VNX series, VNXe series, Symmetrix VMAX, and RecoverPoint.

It enables you to have an application focus when managing your data copies. It enables discovery and management of applications, and instruments them as necessary to ensure consistent and recoverable copies. For example, Replication Manager can place Oracle database into hot backup mode, initiate a copy, and return the application to normal operations. It also supports application-level restore and recovery.

Replication Manager can simplify management of storage replication and integrate with critical business applications. You can use it to create, mount, and restore point in-time replicas of databases or file systems residing on supported storage systems.

It automates management of point-in-time replicas from the context of the application by placing them in a known state prior to taking a replica, essentially creating application-consistent replicas. It discovers and maps applications on the host to the underlying storage infrastructure to ensure it knows the location of the production database prior to taking a replica.

As a Replication Manager Administrator, who can perform all the functions within Replication Manager, you can delegate replication tasks to others within the organization through various user roles with varying degrees of privileges. This improves efficiency through the elimination of scripting activities and delegation of replication tasks.

Replication Manager delivers point-and-click replica management for instant restore back to production (creating a gold copy of production data for instant restore should a corruption occur). Also deal for backup acceleration, Replication Manager streamlines the backup of production data without impacting performance. Similarly, you can create copies of your production database for data repurposing activities such as testing, development, reporting, and training to minimize the impact to production and leverage your production data to perform double duty.

Benefits of Replication Manager:

Replication Manager has the following benefits:

. Automated management of point-in-time replicas VNX Storage.

. Application consistent replication of Microsoft, Oracle, and UDB applications.

. Reduces or eliminates the need for scripting solutions for replication tasks.

. Provides a single management console and wizards to simplify replication tasks.

. Improved recovery and restore features, including application recovery.

. Integration with physical, VMware, Hyper-V, or IBM AIX VIO virtual environments.

Replication Manager offers Application-consistent replication :
In the case of replicating Microsoft Exchange ,SQL Server, and SharePoint, the calls to Volume Shadow Copy Service (VSS) andVirtual Device Interface (VDI) are part of the product specifications. Replication manager automates the process and maintains application consistency.

The EMC VNX Plug-in for Oracle Enterprise Manager 12c:

Is an EMC VNX system monitoring solution for Oracle systems with Oracle Enterprise Manager 12c. The plug-in can reduce the complexity and cost of managing applications that rely on EMC VNX systems and Oracle technologies. Application administrators can use the plug-in to consolidate the monitoring information in Oracle Enterprise Manager and perform comprehensive root cause analysis. Storage and database administrators can perform proactive monitoring of EMC VNX systems, identify the impact of storage performance problems on end-user services, and better align their efforts with business needs.

VNX Snapshots vs. SnapView terms:

The following table shows the consolidated difference between VNX Snapshots and SnapView terminology.

EMC Storage Best Practices for Oracle Redo Log:

EMC does not recommend caching redo logs, archives, or Clusterware files

Oracle redo logs have a very predictable sequential write workload, and this type of activity does not benefit significantly from up-tiering to SSD. Exclude these logs from any FAST policy, or pin them to a 10k rpm or 15k rpm drive tier so that FAST VP will not include them in its analysis.

For Oracle database objects, it is recommended to focus the FAST VP optimization on data, indexes and even temp files, and leave redo log and archive log files outside of FAST VP control. The reason is that redo log devices experience sequential read and write activities, and archive log files are sequential writes. All writes in VMAX go to cache and are acknowledged immediately to the host (regardless of storage tier). For sequential reads, the different disk technologies at the storage array will have minimum impact due to I/O prefetch and reduced disk head movement (in contrast to random read activity). RAID-1 is recommended to ensure the highest performance for sequential writes due to the high write rate typical of redo logs.

EMC recommends to separate data and log files to two different ASM disk groups in the following cases:

For performance and availability reason, redo log writes are synchronous and require to complete in the least amount of time. By having them placed in separate storage devices, the commit writes wont have to share LUN I/O queue with large async buffer cache checkpoint I/Os. Placing the logs in different thin devices than the data make it possible to use a different thin pool and therefore have an increased availability value (when the thin pools dont share spindles) and possibly different RAID protection (when the thin pools used different RAID protection)

When Time Finder is used to create a clone that is a valid backup image of the database, in order for the restore not to overwrite the online redo logs, they should be placed in separated devices and a separate ASM disk group

Why SSD is not the best for Oracle redo log:

In recent years, Solid State Drive (SSDs) based on flash media and not bound by mechanical limitations have come to market. As single SSD is capable of random I/O that would require hundreds of hard drives to match. However the write performance of SSDs is very different from the read performance as SSDs have much better access times, but typically are slower in terms of transfer rates. The internal structure of Flash SSDs use a collection of bytes called an erase block, when you write to a Flash SSD, the drive itself cannot just update the sectors you are changing, but must merge your changes with existing data to update a complete erase block. It is because of these large erase blocks that Flash SSDs are slow at random and sequential writes.


High availability and data protection for Exchange Server on EMC storage

In Exchange 2010 and Exchange 2013, Microsoft introduced the DAG feature to enhance its native Exchange high availability and data protection capabilities.

Exchange DAG:

A DAG, or database availability group, is a set of Microsoft Exchange Server Mailbox servers that can provide automatic database-level recovery from a database, server, or network failure. Mailbox servers n a DAG (16 maximum) monitor each other for failures. When new Mailbox server is added to a DAG, it works with the other servers in the DAG to provide automatic, database-level recovery from database, server, and network failures. You can extend DAGs to multiple sites and provide resilience against datacenter failures.

EMC has a number of data protection products and options that complement DAG and can help further protect your Exchange environment from the loss of a database,server, or an entire site. This section describes various Exchange server high availability and disaster recovery options.

Lagged copy:

If a past point-in-time copy of mailbox data is required, Exchange provides the ability to create a lagged copy in a DAG environment. This can be useful in the rare event that a logical corruption replicates across the databases in the DAG, resulting in the need to return to a previous point in time. Lagged copies can also be useful if someone accidentally deletes mailboxes or user data. One of the disadvantages of lagged copies is that they cannot provide multiple point in-time recoveries. After using a lagged copy for recovery, you must create a new lagged copy. This process may be resource and time consuming in large environments. For additional information about Exchange database corruption types and lagged copy limitations, go to 51 58.aspx

EMC snapshots:

provide the same or better protection Levels using far less storage.

EMC replication technologies:

such as VNX Snapshots, TimeFinder Snaps, and RecoverPoint provide instant point-in-time recovery from a snapshot.

EMC storage-based replication compared to native host-based DAG replication :

Exchange 2013 and Exchange 2010 include a third-party replication API that enables organizations to use third-party synchronous DAG replication solutions instead of the built-in continuous DAG replication feature. Microsoft fully supports third-party solutions that use this API, as long as the solution provides the necessary functionality to replace all native continuous replication functionality that is disabled as a result of using the API. More information about third-party APIs can be found in the online Exchange technical documentation at 37(v=exchg.1 50).aspx#API . EMC is the first company to implement third-party API functionality and allow customers to use their existing SAN and storage-based replication with DAG in third party mode instead of native host-based replication. EMC implements third-party API replication with EMC Storage Integrator (ESI) for Windows suite. This free product allows Exchange Administrators to configure Exchange and to provision, monitor, and automate storage tasks from Microsoft management consoles for a wide variety of EMC storage arrays. This solution provides significant cost and storage savings over using native DAG replication. Using storage-based replication frees up mailbox server (CPU & memory) and network resources when native host-based replication is used. This solution eliminates the need to deploy hundreds of database copies from your Exchange environment, but still provides full protection and high availability to users.

EMC Storage Integrator (ESI) for Windows :

EMC allows Exchange administrators to be in control of provisioning and optimizing storage for their Exchange environment with EMC Storage Integrator (ESI) for Windows Windows Suite. The ESI for Suite is a set of tools for Microsoft Windows and Microsoft applications administrators. The suite includes features and functionality that allow you to manage your applications on premises or in the private cloud. Specifically, the ESI Exchange Integration feature enables you to integrate Microsoft Exchange with supported EMC storage systems. This integration combines the ESI Microsoft Exchange Adapter, the ESI Exchange High Availability (HA) Extension, the ESI Exchange SCOM Management Packs, and the Exchange cmdlets in the ESI PowerShell Toolkit. In addition, ESI provides a utility for optimizing VNX pool LUNs for Exchange workload. You can connect and manage Microsoft Exchange storage as follows:

. Discover Exchange mailbox databases, mailbox database copies, mailbox servers, and DAGs

. Associate Exchange objects with applicable EMC storage-system objects

. Create and remove Exchange mailbox databases

. View database copy status in the ESI GUI or with the ESI PowerShell Toolkit

. Add and remove mailbox database copies for high availability and site resilience

. Create, provision, and remove storage for mailbox databases

. Use the ESI PowerShelL Toolkit to automate storage-provisioning and high availability tasks

. Use the ESI for VNX Pool Optimization utility to improve performance of storage pool-based thin and thick LUNs for Jetstress pre-deployment validation

. Use EMC RecoverPoint to enable Exchange third-party DAGs (in third-party replication mode) for high availability

. Use the ESt Exchange SCOM Management Packs to monitor the [SI Exchange HA Extension in SCOM. You can use SCOM to ensure that the extension is running and to generate alerts for possible remediation failures.

VNX Snapshots:

Is a VNX software feature that creates point-in-time data copies that customers can use for data backups, software development and testing, repurposing, data validation, and local rapid restores. Depending on your application requirements, you can create VNX Snapshots and snapshots of VNX Snapshots. VNX Snapshots support 256 writable snaps per LUN and up to 32,000 per system, depending on the VNX system size. VNX Snapshots do not replace SnapView technology. In fact, both features can coexist. VNX Snapshots supports Pool LUNs,while VNX SnapView supports RAID Group LUNs. In addition, SnapView clones can have their own VNX Snapshots. Unlike SnapView snapshots and clones, VNX Snapshots do not consume large amounts of pooi capacity. As a result, this feature is preferred for modern data management.

VMAX TimeFinder Snaps :

Software creates snapshots that are virtual point-in-time copies of a LUN. Snaps are comprised of data that resides on the source LUN and on the save devices. The data on the save devices consists of copies of the original source LUN data that have been modified since the snap was taken. When a snap is taken, the production host is still able to write to the source LUN and modify data. When this occurs, the software stores a copy of the original data in the save devices. This operation is referred to as copy on first write and occurs only once for each chunk of data that is modified on the source LUN. TimeFinder snaps have minimal to no impact on the Exchange servers during backups. When used in combination with EMC Replication Manager, snapshots are application-consistent because they are created within the VSS framework.

EMC data protection offerings: for Exchange (with VNX Snapshots or RecoverPoint) are:

EMC RepLication Manager (EMC RecoverPoint, EMC SnapView, EMC TimeFinder)

EMC AppSync (VNX Snapshots, EMC RecoverPoint)


EMC Networker

Each of these listed solutions has its own strengths and capabilities. The choice depends on the individual customers requirements for backup and restore and what type of EMC storage array they currently have or are planning to acquire in the future.

EMC hardware-based snapshot and clone products have been integrated with Microsoft VSS technology for many years. TimeFinder, VNX SnapView, and VNX Snapshots enable you to create local point-in-time snapshots or data clones for backup and recovery operations. These products enable simple, non-destructive backup operations with space-saving snapshots or full block-for-block clone copies of your databases and logs. With these products, backups and restores can occur in seconds.

EMC Replication Manager:

Enables the management of EMC point-in-time replication technologies through a centralized management console for both VNX and VMAX system s. Replication Manager coordinates the entire data replication process from discovery and configuration to the management of multiple, application-consistent,disk-based replicas.

Replication Manager uses the VSS functionality provided by Microsoft that facilitates the creation of application-integrated snapshot backups. Specifically, Replication Manager provides support for Exchange Server snapshots using Volume Shadow Copy Service (VSS). Replication Manager supports Exchange Server 2010/2013 in standalone or DAG environments.

EMC AppSync:

Offers a simple, self-service SLA-driven approach for protecting virtualzed Microsoft applications in VNX deployments. After defining service plans, application owners can protect production data and recover data quickly with items level detail. AppSync also provides an application protection monitoring service that generates alerts when the SLAs are not met.

The Advanced Protection for Microsoft Exchange2l O on EMC VNX Storage whitepaper provides a complete solution using Exchange with EMC AppSync and VNX snapshots. The Reterenes section on page 45 provides more information.

Rapid Exchange backup and restore:

EMC strongly recommends a robust method of enabling rapid Exchange database backup and restore . EMC AppSync, [MC Replication Manager, EMC Avamar, and EMC Networker offer features for log truncation and the mounting of databases to alternative hosts.

Even if the native Microsoft Exchange DAG feature is used with or without a lagged copy, EMC strongly recommends an aLternative, solid, point-in-time Exchange data protection strategy to guard against Logical corruption events.

EMC ItemPoint:

In EMC Replication Manager or [MC AppSync, there is an option to install [MC Item Point. EMC Item Point for Microsoft Exchange Server works with your existing Microsoft Exchange Server backup architecture and procedures and allows you to recover individual mailboxes, folders, messages, attachments, calendar items, notes, and tasks directly to your production Microsoft Exchange Server or any Personal Folders (PSi) file. This eliminates time. Consuming and expensive single mailbox (brick-level) backups. This powerful software also lets you search and create a copy of all archived email that matches a given keyword or criteria. The References section on page 4 provides more information.

Disaster recovery options for Exchange:

EMC offers various disaster recovery (DR) options for Exchange Server. Table 14 presents the three most popular options in addition to the native Exchange DAG feature. Each option has its advantages and disadvantages. Your specific DR requirements determine the best option for you.

You can also manage your VNX snapshots using EMC AppSync, software that provides application consistent snapshots for Microsoft Exchange and SQL Server, and provides crash-consistency for VMware VMFS datastores. The AppSync GUI allows you to manage, configure, catalogue, and schedule your VNX snapshots.


About Ahmad Sabry ElGendi
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