Hello,
Disk access name is the first column in above output "hdisk1" etc which indicates the disk names volume manager has already scanned & detected. This name depends on two things
1. What array support library has installed & claimed the devices. Array Support Library (ASL) is like a driver for the stroage which helps VxVM to efficiently work with storage
2. What is the naming scheme you have selected in Veritas, there are 2 possibilities, OSN (Operating system Naming) or EBN (enclosure based naming)
Disk Media name is the third column where you can give more meaningful name to a disk. Consider a system with 1000 disks, it will be difficult for you to identify which disk belongs to which diskgroup, so you can give meaningful name like oradg01 which will indicate that disk belongs to oracle dg & used for database. VxVM will use disk access & media names in various commands, you need to learn to map them both each other using "vxdisk list" output or "vxdisk -e list" output
lastly, keep reading the guide, will help you build lot of basics & understanding on the product.
G
