Using VMWare for DRP with Intersystems' Cache database
Posted on 2009-05-09
This question is about using VMWare infrastructure for DRP, for a critical machine holding an application based on Intersystem's Cache database.
We're trying to build a disaster recovery plan for a critical machine in our organization. The pysical machine is Windows 2003 server with a database named Cache (by Intersystems). The OS is insalled on the machine's mirrored disks, and the data volume is located on a SAN LUN (on EMC CX3-40).
We have an additional EMC CX3-20 that we intend to locate on a remote DR site.
The plan is to use P2V to make the production machine a VM, and then locate the VM machine on an EMC LUN.
Then, replicate this machine to the DR site, and put it on the remote CX3-20, and make sure the DR VM is synced with the production VM.
The idea is that if something bad happens to the production VM, we *manually* start the remote DR VM one. The RPO and RTO are not that critical. The RPO could be few hours, and the RTO is one day.
The questions are as follows:
A. What VMWARE infrastructure should we use to replicate the production VM machine to the VM on the DR site?
B. How do we sync between the two machines? Should it be done using VMWare infrastructure, or better using storage to storage replication tools (such as EMC's) ?
C. How can we make sure that if the production VM machine is not functioning anymore (and of course there are several scenarios of why this could happen), the DR VM *database* will be consistent?
I'll explain more about question C : I guess we could solve the 'consitency' question by going to hot backup mode on the production machine several times day(flushing all RAM to the disk etc.), and while in backup mode we could replicate the changes to the remote DR VM. But going to hot backup mode makes the production VM database work very slow. Is there a better way suggested by VMWARE for VM to VM replication, while making sure the database is consistent in the remote machine?