iSCSI LUNS replication and initial copy strategy

Question

Hello folks, I'm setting up an iSCSI replication environment where I have 2 Celerra both in same NAS code version (5.6.42-5) and already running virtual machines in my volumes. I have 4 LUNS each 500GB (VMFS3) from my source and other 4 LUNS 500GB in my destination, the same with readonly permission. With this scenario I have some concerns and some strategies doing the initial copy from my source LUN to destination LUN. To lower my time consumption and thinking not to consider my link (4Mbps) between sites to start this initial copy I thought and did a VCB full-image backup from my 4 source LUNS saving my virtual machines in USB external disks. Untill now OK... In my destination 4 LUNS each with 500GB were created, set up into other targets and configured into my ESX Servers to allow executing my strategy from using a full-image backup done by VCB in my source converting this full-images with Converter Enterprise into my 4 destination LUNS already with VMFS3 file system populating the volume. After remove mask to this LUNS, remove connections from initiator, just leaving the LUN and target together tried to replicate my first source 500GB LUN to my destination 500GB LUN that is already populated with vitual machines files and also in readonly but the wizard pop up me an error message that my destination target does not have a readonly LUN or the size ins not compatible. To troubleshoot all possibilities I created a 10GB LUN, delivered to my source ESX created a vm and created a replication to other 10GB LUN in my destination without any preparation only in readonly and worked as well. My main questions are: 1 - Does my strategy did not work using VCB from my source and Converting into my destination and later just replicate the deltas cause the destination LUN cannot be populated anyway before start replication? 2 - Are there some other possibilities doing these LUNS initial copy to reference my source objects in my destination without using link nor tape transport ? Thanks a lot to every idea this will be very welcome!

Peter_EMC · Answer

For 'normal' replications there is the 'tape transport' or 'tape silvering' method, which is doing something like your are describing.But this is not supported for iSCSI Luns.If you want iSCSI Luns replicated, there is no way to avoid the initial copy over IP.Sorry.Regards Peter

Rainer_EMC · Answer

you can open a Product Enhancement Request through Powerlink if you feel this is needed more often

vitera-kaizen · Answer

Hi Rainer,I guess this really could be more often cause we (consultants/engineers) do integrations with VMware environments and also leveraging IP Storage Celerra has a great trend to be always more used in any environments and scopes.This enhancement could really be a differential to other products, and ease of use to this specific scope etc.A great scenario could be:Source LUNS - VMFS3 ----ReplicatorV2--------> Destination LUNS - VMFS3 | |VMware VCB full-image ------Tape/DiskTransport----> Converter EnterpriseThat's fine and thank you very much for this fast response, I really needed this point of view to formal introduce this fad.Regards.

Celerra

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