Hi C2020,
Here is what I would do.
Process:
Perform base config of the MDS 9148S (Mgmt IP etc.)
• Check that the MDS 9148S domain ID is numerically higher than the MDS 9148 domain ID
• Connect MDS 9148S and MDS 9148 in the same fabric
• Merge the fabrics, this copies the configuration to the new switch
• Move storage array ports one-by-one to the new switch
• Check host connectivity after moving each port
• Done!
Few things to note (verify):
• Verify and enable enhanced device alias mode
• device-alias mode enhanced device-alias commit
• Create necessary VSANs on the new switch
• Verify and enable enhanced zone mode / smart zone mode
• Switch priority range from 1 to 254, default is 128
• Priority 1 has the highest priority
• During the principal switch selection phase;
• Switch with the highest priority becomes the principal switch
• If configured same priority, the switch with the lower WWN becomes the principal switch
• Domain ID and Priority determines Principal Switch selection
• The principal switch copies its config to all subordinate switches
• Use this behavior to help you migrate to your new switches
• But be careful – make sure right domain-id and priorities are set before connecting them
Here is a nice TAC note / Config example: https://www.cisco.com/c/en/us/support/docs/storage-networking/mds-9500-series-multilayer-directors/117621-configure-MDS-00.html