Non-disruptive intrasite metro volume migration

A system comprising:

• one or more processors;
• and
• one or more memories comprising code stored therein that, when executed, performs a method comprising:
• configuring a metro volume for bi-directional synchronous replication from a volume pair (V1A, V2), where V1A is included in a first site and V2 is included in a second site, wherein V1A and V2 are configured to have a same identity, a first identity of a first logical device, when presented to external clients over i) first paths from the first site and ii) second paths from the second site;
• and
• performing migration processing to migrate V1A to another volume V1B of the first site, wherein the first site is a migration site and wherein the second site is a non-migration site, said migration processing including:
• internally assigning i) the migration site a non-preferred role in which the migration site is not to remain online when the metro volume is fractured, and ii) the non-migration site a preferred role in which the migration site is to remain online when the metro volume is fractured;
• pausing the metro volume including fracturing the metro volume thereby disabling the bi-directional synchronous replication with respect to the volume pair (V1A, V2), wherein V1A denotes a first point in time copy of the metro volume when the metro volume is fractured by said pausing;
• in response to said fracturing the metro volume, removing access to the metro volume through the migration site having the non-preferred role whereby all I/Os directed to the metro volume from the external clients are directed to the non-migration site having the preferred role;
• receiving, at the non-migration site while the metro volume is fractured, first writes directed to the metro volume where the first writes are applied to V2 configured as the metro volume;
• after V1A and V1B are synchronized to the first point in time copy of the metro volume, enabling the metro volume for bi-directional synchronous replication from a second volume pair (V1B, V2), wherein V1B and V2 are configured to have the same identity, the first identity of the first logical device, when presented to external clients over i) third paths from the first site and ii) the second paths from the second site, wherein said enabling includes:
• synchronizing V1B and V2, including applying the first writes to V1B, where prior to said synchronizing, the first writes had been applied to V2 and the first writes had not been applied to V1B;
• and
• in response to said enabling the metro volume for bi-directional synchronous replication from the second volume pair (V1B, V2), providing access to the metro volume configured as the second volume pair to the external clients from both the migration site and the non-migration site.

One or more non-transitory computer-readable media comprising code stored thereon that, when executed, performs a method comprising:

• configuring a metro volume for bi-directional synchronous replication from a volume pair (V1A, V2), where V1A is included in a first site and V2 is included in a second site, wherein V1A and V2 are configured to have a same identity, a first identity of a first logical device, when presented to external clients over i) first paths from the first site and ii) second paths from the second site;
• and
• performing migration processing to migrate V1A to another volume V1B of the first site, wherein the first site is a migration site and wherein the second site is a non-migration site, said migration processing including:
• internally assigning i) the migration site a non-preferred role in which the migration site is not to remain online when the metro volume is fractured, and ii) the non-migration site a preferred role in which the migration site is to remain online when the metro volume is fractured;
• pausing the metro volume including fracturing the metro volume thereby disabling the bi-directional synchronous replication with respect to the volume pair (V1A, V2), wherein V1A denotes a first point in time copy of the metro volume when the metro volume is fractured by said pausing;
• in response to said fracturing the metro volume, removing access to the metro volume through the migration site having the non-preferred role whereby all I/Os directed to the metro volume from the external clients are directed to the non-migration site having the preferred role;
• receiving, at the non-migration site while the metro volume is fractured, first writes directed to the metro volume where the first writes are applied to V2 configured as the metro volume;
• after V1A and V1B are synchronized to the first point in time copy of the metro volume, enabling the metro volume for bi-directional synchronous replication from a second volume pair (V1B, V2), wherein V1B and V2 are configured to have the same identity, the first identity of the first logical device, when presented to external clients over i) third paths from the first site and ii) the second paths from the second site, wherein said enabling includes:
• synchronizing V1B and V2, including applying the first writes to V1B, where prior to said synchronizing, the first writes had been applied to V2 and the first writes had not been applied to V1B;
• and
• in response to said enabling the metro volume for bi-directional synchronous replication from the second volume pair (V1B, V2), providing access to the metro volume configured as the second volume pair to the external clients from both the migration site and the non-migration site.