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Introduction to Live Migrate and Volume Advisor
8 Dell EMC SC Series Live Migrate and Volume Advisor | 3186-BP-SC
1.1.3 After role swap
Once the destination SC Series array is in sync with the source array as shown in Figure 4, all the existing
volume data resides on the destination array. New writes can be quickly acknowledged and replicated so that
a role swap can be performed. By default, Live Migrate configures this to occur automatically, which is
preferred in most cases where Live Migrate is being leveraged to address an existing problem or pending risk.
However, it may be configured as a manual task if desired. After the role swap, the volume (1) on the
destination SC Series array becomes the target volume for all writes. Writes received by the source array are
forwarded (2) to the destination array and acknowledged. Writes received by the destination array are
acknowledged but not replicated back to the volume (3) on the source SC Series array. This is also the case
with read I/Os.
Data paths after role swap
1.1.4 Completion
Once the role swap has occurred, new writes are no longer committed to the source volume, but the server is
still mapped to it and may be sending I/O to it depending on the server’s path selection policy. The storage
administrator must mark the Live Migrate task as completed, which will offline the volume (1) and remove the
mapping between the server and volume on the source SC Series array. It is important to emphasize that in
this step, paths will be removed from the volume on the source array. A storage rescan should have been
performed as part of the step, During data movement (section 1.1.2), and verified that the server recognizes
available paths to the volume on the destination array so that there is no storage interruption in the step, After
role swap (section 1.1.3). Now, the server is only mapped (2) to the volume (3) on the destination SC array,
shown in Figure 5. The administrator can now delete the original volume on the source SC Series array (1).
Configuration of environment after Live Migrate