re: Types of failover operations in Hyper-V Replica–Part III - Unplanned Failover

yummy_sammich — Tue, 01 Jan 2013 08:49:30 GMT

Oliver,

Simple answer:

Planned failover: absolutely!

Unplanned failover: it can if you configure it to (with certain limitations).

Longer answer:

Hyper-V Replica, in its most basic configuration, replicates VM storage by committing VM storage-level changes to a local replication queue as frequently as every 5 minutes and replicating that data to the replica as fast as the available bandwidth and throttling settings allow. This is an excellent DR starting point as your replicated disk-committed data is successfully stored offsite. As this functionality is storage-focused and application-unaware, you will be presented with your standard application dirty-shutdown scenario upon booting the replica after an unplanned failover. Planned failovers will result in zero data loss and data integrity will be maintained.

Hyper-V Replica really earns its salary bonus in two ways. First, it provides you with a warm DR site topology by replicating VM settings. This will allow you, at the very least, to bring your server platform online at the DR site in the event of an unplanned failover. If data-integrity issues are present, data can be pulled from backup. Second, and more importantly, Hyper-V Replica supports initiating VSS-initiated, application-consistent snapshots as frequently as every hour. If Oracle heeds the vss-initiated quiesce command, then VM and the database data will be captured in an application-consistent state. This means that if a full copy of one of these snaps (snapshots) makes it to the replica servers, you have a great chance of maintaining data integrity during an unplanned failover. Once again the interval has a minimum interval of 1 hour so this is clearly DR-focused, so an RPO for consistent-data of 1hr+ is to be expected.

With that in mind, the measure of application compatibility should be based on what your business needs are, made up of the RPO/RTO's and data integrity assurances that can be delivered by the different configurations listed above.

re: Types of failover operations in Hyper-V Replica–Part III - Unplanned Failover

Oliver Richter — Tue, 30 Oct 2012 20:25:55 GMT

Hi,

can someone tell me whether a virtual server (HYPER-V guest) of Oracle (10 g One), supports the HYPER-V replication? Is there a white list of applications that support HYPER-V Replica? Thanks.

re: Types of failover operations in Hyper-V Replica–Part III - Unplanned Failover

Praveen Vijayaraghavan,MSFT — Fri, 26 Oct 2012 05:46:07 GMT

Hi Brian,

Once the original primary site is up, using Hyper-V Replica, you can reverse-replicate the changes to the primary server and then perform a Planned-Failover from the replica site back on the primary site.

Praveen

re: Types of failover operations in Hyper-V Replica–Part III - Unplanned Failover

BrianEh — Tue, 25 Sep 2012 14:40:24 GMT

Sicne this is unplanned. You are missing one key part. Failing back.