The document discusses DataCore's Advanced Site Recovery (ASR) solution. ASR allows organizations to distribute disaster recovery responsibilities across multiple smaller locations rather than relying on a single large disaster recovery site. It uses bidirectional replication between sites to keep disaster recovery locations up to date and allow workloads to failover seamlessly between primary and secondary sites during planned or unplanned outages. The key benefits of ASR are that it is fast, automated, universal in supporting different workloads, distributed across multiple sites, bidirectional to enable workloads to resume at the original location, and makes disaster recovery testing and verification easy.
Many organizations with large central IT facilities rely on regional branch offices to better serve their customers. These branches have modest computing power and network connections.
However, most of the thinking around Disaster Recovery attempts to offload the central IT workload to one large site. This choice drives the need to beef up the contingency location so that it can adequately cover for central site outages. Such design philosophy is driven by constraints of the devices, particularly high-end storage systems, used to replicate data between the sites. Basically, organizations must replicate not only data, but the physical storage systems at both ends to make this work. Server virtualization places no such requirements on the processing engines.
The Advanced Site Recovery component of DataCore’s comprehensive business continuity portfolio allows central IT organizations to cost-effectively spread disaster recovery (DR) responsibilities among several smaller sites, allowing each of them to accept a more manageable role in keeping the business going.
Spread DR responsibility across multiple sites (e.g., branch offices)
Choose contingency sites best suited to handle additional load during DR
Example
DR site x: Mail Server & Database Server
DR site y: Business Apps 1-3
DR site z: Business Apps 4 -7
A production VVol (VMFS-DS1) that is accessed from the ESX server farm in the production site (site A) is replicated thru a WAN link to a helper VVol (L1) the DR site (site B).
The helper VVol L1 gathers all the replicated data changes. Once an hour the latest state is moved to the production VVol peer (VMFS-DS1) on the DR site via periodic snapshot update.
All data changes are replicated back to the production site to another helper VVol (L2). The helper VVol L2 gathers all data changes made on DR site for later failback to the primary site.
In case of a failover to DR site is needed the production VVol replica on DR site will be promoted (mapping to spare ESX server activated) and VMs can be re-started in the DR site.
Buffers on production and DR site ensure that data is stored as long as sites and/or link in between aren't available.
In case of later failback to primary site a pre-defined snapshot is being executed that moves all the data changes, which occurred during operation in DR site, back to the production VVol and VMs can be re-started in their original location.
To restore the primary site, a pre-defined snapshot is being executed that moves all the data changes, which occurred during operation in DR site, back to the production VVol and VMs can be re-started in their original location.