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Introduction to Live Migrate and Volume Advisor
7 Dell EMC SC Series Live Migrate and Volume Advisor | 3186-BP-SC
1.1.2 During data movement
Figure 3 shows that once Live Migrate is configured and running, the server (1) is mapped to both the source
volume (3) on the source SC Series array and the newly created destination volume (4) on the destination SC
Series array. Data is asynchronously replicated from the source SC Series array to the destination array using
the configured replication connection fabric (5). The source volume and destination volume appear to the
server as a single volume with additional paths (2). The server cannot distinguish between the paths leading
to the source volume and those leading to the destination volume. The server may send I/O down any
available path. The path selection policy will determine which path(s) are used. If the source and destination
SC Series arrays are running SCOS version 7.3 or newer, and the server is using an ALUA-aware round
robin path selection policy, this will also dictate which path(s) are actively used. Regardless of which array
receives the I/O, it will be handled correctly. During the Live Migrate, but before the role swap, read I/O
requests can be serviced by the array that receives the request. In the case of the destination array receiving
a read request for a page that has yet to be replicated, the read request will be forwarded (6) to the source
array. Write I/Os received by the source array are acknowledged and replicated asynchronously. Writes
received by the destination array, are forwarded (6) to the source, acknowledged, and replicated
asynchronously. The replication progress and sync status of the Live Migrate operation can be observed on
the volume Summary screen and on the Live Migrate page under Replication and Live Volumes.
Data paths during Live Migrate