A customer plans to replace a McData 6140 core director with a Cisco MDS 9506. The storage is based on SVC with three DS5300 back-end storage systems. The storage resources are attached to the 6140 core while all servers are attached to edge switches. Linux, Windows and AIX servers use the SVC. Which of the following is a potential risk associated with this planned migration?（）
- A thereare no potential risks
- B the FCIDs of the servers must be changed
- C the SVC must be shut down during the migration
- D changing the FCIDs of storage resources will impact some server