Data Replication 4TB using CA

[Balakrishna Kotian]

Hi, Can any one confirm me if I use CA for replicating data between EVA3000 to EVA4000 will it replicate bit by bit or I can backup and restore data at other side and do replication. As I have data of 4TB on either side which needs to be replicated on both EVA(Bidirectional). As per my assumption EVA does bit by bit replication so the initial replication (for 1st time) will take as long as 100 days with 10Mb bandwidth between both sites. We wanted to use hardware soultion for data replication or the other alternative is using some compression box between the WAN link.

Regards,

Bala

[Uwe Zessin]

From what I have heard, the EVA only replicates those segments of a virtual disk which have already been written by a host. In the worst case, however *all* data needs to be moved by CA.

[Balakrishna Kotian]

Hi Uwe, I too know the same but recently I heard that with the new firmware for the controllers and updated management software can handle it. So I wanted to find out is there any documents available stating Yes its possible. If the initial replication will take for months then what will happen if disaster happen and to restore it will take months. There are couple of software based solution but looking something really on hardware.

Txn

Bala

[Erwin van Londen]

Bala,

The thing you can do is keep both arrays on one location with one fibrechannel switch between them. Let the array replicate, suspend the CA process, move the array to the other location, connect the EVA to the SAN and resume the CA replication. This is the fastest way of doing it if you have a slow bandwidth connection between them. Make sure however that the source array has enough free diskspace for logging because otherwise it will do a full copy again.

If however this is a new installation and you create fresh Vdisks it will only copy the written blocks like Uwe said in the previous message.

Gr
Erwin van Londen
HP Master ASE SAN Architect.

[Balakrishna Kotian]

Hi Erwin,

You got a good solution which we also had it in mind but We cannot get both EVA box together bcuz its accross two countries. The option we are looking like take a intial full backup on tape and send it across, restore it and then start the replication. Bcuz if disaster strikes then restoring back is also important where we cannot get the EVA back to the local site for replication. Boxes on either side are having data and now we are adding additional disk and create new DG and do replication. Will this improve to use CA or would like to know with new VCS 3.028, CV 4.1, BC 3 and CA 2 doesn't it make any new improvement as compared with the features provided by other software vendor.

If you think this will work kindly let me know as we cannot test a lot as these are production systems.

BR
Bala