RecoverPoint

RecoverPoint is a continuous backup solution offered by EMC Corporation. Capabilities include bi-directional asynchronous and synchronous data replication across heterogeneous storage arrays. Block based storage is supported as of today, both FC and iSCSI. All replication takes place over standard IP for asynchronous replication and Fibre Channel for synchronous replication. RecoverPoint handles FC to IP conversions for asynchronous replication.

The core behind this product’s ingenuity is its block based journaling and WAN based compression capabilities. Every write (or groups of writes) are aggregated together into a single snapshot for distribution. Snapshots are important in comparison to mirroring technologies due to the fact Garbage In equals Garbage Out. If Logical corruption manifests itself on the source volume it will be replicated to the destination volume. This is not the case with snapshot based technology, as each snapshot is a point in time of the production volume. Delineation between one snapshot and another is hard defined. Therefore with any snapshot there will be a “before and after” view of the production volume. The before being prior to logical corruption, the after being post corruption. Mirroring is a moving target, its only a matter of time before the logical corruption becomes viral and infects the remote copy. Therefore journal based replication is the future and the “now” of local and site to site replication.

Replication

RecoverPoint Continuous Data Protection (CDP) tracks changes to data at a block level and journals these changes . The journal then allows rolling data to a previous "Point-In-Time" in order to view the drive contents as they were before a certain data corruption. CDP can journal each write individually, hence enabling "Any-Point-In-Time" snapshots, or it can be configured to combine consecutive writes in order to reduce journal space and improve bandwidth. CDP works only over SAN - the RecoverPoint appliances needs to be zoned and masked with both the master, the replica and the journal LUNs.

RecoverPoint Continuous Remote Protection (CRR) allows a replica in a remote site. For such a setup, RecoverPoint appliances clusters are required in both the local and remote sites. These 2 clusters communicate over IP. RecoverPoint applies compression and de-duplication in order to reduce WAN traffic. As of RecoverPoint 3.4, only one remote site. CRR can be combined with CDP in order to provide Concurrent Local and Remote (CLR) replication.

The consistency group (CG) term is used for grouping several LUNs together in order to ensures write-order consistency over several volumes. This is used for example with a database that stores its data and journal on different logical drives. These logical drives must be kept in-sync on the replica if data-consistency needs to be preserved. Other examples are multi-volume file systems such as ZFS or Windows' Dynamic Disks. RecoverPoint 3.4 supports up to 128 CGs and 2048 LUNs . Each LUN can contain up to 2 TB, and the total supported capacity can be up to 150 TB.

Write Splitting

Unlike periodic backups, but similar to other replication products, RecoverPoint needs to obtain a copy of every write in order to track data changes. RecoverPoint supports 3 methods or write splitting: host-based, fabric-based and in the storage array. EMC advertises RecoverPoint as Hetrogenous due to its support of Multivendor server, network and storage environments .

Host-based write splitting is done using a driver that is installed on the server accessing the storage volumes. The usage of a host-based splitter allows replication of non-EMC storages. However, splitters are not available for all operating systems and versions.

Available Fabric-based splitters are for Brocade SAN switches and for Cisco SANTap. This requires the investment in additional switch blades which cost money. This configuration allows splitting from all operating systems regardless of their version, and is agonistic to the storage array vendor.

Storage array splitters are only supported on a subset of EMC storages. This method allows write splitting from all operating systems, and does not require special SAN switching hardware. The RecoverPoint/SE is a slimmed-down version that only supports this type of splitters.

Integration with other products

Beyond integration with EMC products such as the Clariion storage array, Replication Manager and Control Center, RecoverPoint integrates with the following products:

Integration with VMWare vCenter and Microsoft Hyper-V allows protection to be specified per VM instead of per volumes that are available to the hypervisor.

Integration with Microsoft Volume Shadow Copy, Exchange and SQL Server and Oracle Database Server allows RecoverPoint to temporarily stop writes by the host in order to take consistent application-specific snapshots.

The usage of APIs/CLIs allows customers to integrate RecoverPoint with custom internal software .

References

• EMC RecoverPoint, a Single Solution for CDP and Disaster Recovery
• EMC plans to use Kashya technologies in RecoverPoint
• Continuous Data Protection With EMC RecoverPoint
• EMC Updates RecoverPoint SAN CDP/Replication Engine

External links

• EMC RecoverPoint [1]