initial volume replication - over wan

[edavies]

I am interested to learn the best method of copying a new/additional volume image for the first time from one open-e storage server to a remote one (to set up volume replication) if they are both already in production and we add a new volume at a later date. Can we copy a volume to portable media such as an external USB drive and send it to the remote site and add the volume to the storage server? Should we use snapshot?

[To-M]

You wont be able use portable media such as an external USB drive. Link below provides information on config and setup procedures to assist you that might help.

http://www.open-e.com/library/product-presentations/

Open-E Replications
2008 - Replications supported by Open-E software, March 2009
2008 - Open-E DSS Asynchronous Data Replication over a WAN, April 2009
2009 - Open-E DSS Asynchronous Volume Replication over a LAN, April 2009
2009 - Open-E DSS Asynchronous Volume Replication over a WAN, April 2009
2008 - Open-E DSS Synchronous Volume Replication over a LAN, April 2009
2009 - Open-E DSS Synchronous Volume Replication over a WAN, April 2009
2008 - Open-E DSS Synchronous Volume Replication with Failover over a LAN, April 2009

[edavies]

ok, thanks for that.

We have used these docs, they have been very helpful, and the data replication over a wan is working well.

The only thing we were worried about was once the system was running, for say 6 months, and we decide to add a new volume to the main storage server and then setup replication of that new volume, that it would take considerable time for the initial replication over the wan and we were looking for a way to manually copy just that initial replication (as I gather once the first one is complete it is incrementals afterwards).

[To-M]

Yes and this is a good point as you would have to start from the begging and would take a long time. Currently we don't have any other way unless you can predict the amount of the next volume size and add that just incase to be ahead of the game.

[pturnbull]

Hi Todd,
Are you sure there is no way to do this? Other devices allow for replication jumpstart and especially if used over a WAN seems vital.
something like Portable Volumes to let users use an external USB drive to jumpstart replication. When the system admin creates a replication pair between arrays, the destination and source is created then source array exports the data to the USB disk(s). The admin then drives or ships the USB disk to the standby site and plugs it into the destination array there. Now the link between the sites can be sized for the data change rate
Cheers,

Paul

[To-M]

When using a USB drive it is seen as a Dynamic Volume not as a Volume Group. So this is why it wont work. Now if you have a Disk that is connected via IDE, SATA, SAS or SCSI then yes this would would work. Just make sure to name the volume different then the one your shipping it to.

[pturnbull]

Thanks Todd,

This is a real showstopper for us. If we can't create the volume replication and then move the bulk of the data out of band it will take too long to synchronise over the 1-2Meg links we are talking about using and would take days to replicate the 35Gig volume we are testing with. The subsequent Asynch incrementals are fine but not the initial provisioning. If we did a LAN replication and then moved the array to the DR site all is ok but what if we need to add another volume in the future? In all other areas the Open-E was ideal but I will have to try something else.
Cheers,

Paul

[pturnbull]

Can I just add that the 35Gig is the volume size but the data on this is 10Gig yet the whole volume has to be synch'd block by block. I'm still new to the Open-E so may not have it configured correctly but so far have had to do a back to back replication of the arrays and then moved the destination over the WAN.
Cheers,

Paul

[To-M]

If we did a LAN replication and then moved the array to the DR site all is ok but what if we need to add another volume in the future? In all other areas the Open-E was ideal but I will have to try something else.

Like I said this will work (not from a USB drive though) but you would have to create a Volume Group that will be different to the one it will be in. Also how would you integrate with your RAID controller or RAID set. I understand what you are trying to do and the need for it but there is more to this then just adding a drive. This is a feature we do not have. Though I do think our engineers should look into this.

[To-M]

You can add to the logical volume size but you will need to stop the replication then increase the size on both system then start the replication and yes they will replicate the added size.