Populating a secondary cache with unmodified tracks in a primary cache when redirecting host access from a primary server to a secondary server

A system, comprising:

• a primary server including a primary cache and managing host access to a primary storage;
• a secondary server including a secondary cache and managing host access to a secondary storage;
• wherein the primary server and the secondary server perform operations, the operations comprising:
• replicating updates to tracks in the primary storage to the secondary storage;
• in response to of a failover operation, performing:
• redirecting host access to tracks from the primary server to the secondary server, wherein after the redirecting host access to the secondary server, host access is directed to the secondary server and the secondary storage;
• providing a cache transfer list indicating unmodified tracks in the primary cache to transfer to the secondary cache;
• and
• populating, by the secondary server, the secondary cache with the unmodified tracks in the primary cache at the primary server indicated in the cache transfer list to make the unmodified tracks in the primary cache available in the secondary cache available in the secondary cache to the host access redirected to the secondary server.

A method for redirecting host access from a primary server to a secondary server, wherein the primary server manages access to a primary storage and the secondary server manages access to a secondary storage:

• replicating updates to tracks in the primary storage to the secondary storage;
• in response to a failover operation, performing:
• redirecting host access to tracks from the primary server to the secondary server, wherein after the redirecting host access to the secondary server, host access is directed to the secondary server and the secondary storage;
• providing a cache transfer list indicating unmodified tracks in a primary cache at the primary server to transfer to a secondary cache at the secondary server;
• and
• populating, by the secondary server, a secondary cache at the secondary server with the unmodified tracks in a primary cache at the primary server indicated in the cache transfer list to make the unmodified tracks in the primary cache available in the secondary cache to the host access redirected to the secondary server.