HPE EVA Storage

HP Continuous Access Behaviour

 
SOLVED
Go to solution
IvanForceville
Regular Advisor

HP Continuous Access Behaviour

We're currently doing some testing with CA between two EVA's with an ISL of 50MBit.

We created a 50GB Vdisk with one Virtual machine of 10GB on it.

We started replication from one site to the other which took about 2-3 hours.

When we failover to the other side, HP CA start sycning the other way and replicates the entire Vdisk to the original side, knowing that the data is 99% the same. So, every time we failover/failback the Vdisk is replicated entirely (we presume)

Is this normal behaviour? I thought that HP CA would Check what's left of the LUN on the source side and only move the delta's?

?
6 REPLIES 6
Uwe Zessin
Honored Contributor

Re: HP Continuous Access Behaviour

That does not sound correct. Can you give a little more technical details about your EVA configuration ? (firmware revision, using sync/async replication, ...)
.
IvanForceville
Regular Advisor

Re: HP Continuous Access Behaviour

We have two EVA4400's with FW 09522xxx and are using Async replication.

Distance between sites is 50-60km.

When we failover to the other side, it takes about 1,5 hours to synchronize towards the original side, knowing that there is only 1 Virtual Machine on the LUN which hasn't changed.

Tested this a few times today.
Uwe Zessin
Honored Contributor

Re: HP Continuous Access Behaviour

Do you switch to sync mode before the failover?
.
IvanForceville
Regular Advisor

Re: HP Continuous Access Behaviour

Not realy... But honestly, I need to check. It appears that the copy is in Sync mode but we definately don't explicitly set it.
Víctor Cespón
Honored Contributor
Solution

Re: HP Continuous Access Behaviour

Looks like you're doing an UNPLANNED failover, so a full copy is done.

Read the RSM user guide, it's the best way to understand Continuous Access.

http://bizsupport2.austin.hp.com/bc/docs/support/SupportManual/c02012745/c02012745.pdf

Look for "PLANNED failover"
IvanForceville
Regular Advisor

Re: HP Continuous Access Behaviour

Guys,

You we're correct. There is a difference between Planned and Unplanned failover... Since we were using Vmware Site Recovery Manager to do the failover the process was automated... didn't catch it.

Thx... close case.