For my own ference:
disk space under VMFS-3 is organized according to four resource types. They are : blocks, sub-blocks, pointer blocks, and file descriptors. Resources are grouped into clusters, which form cluster groups. Every resource type is administered by one or a number of system files. Lets have a look at what those abbreviated file names stand for:
- fbb.sf = file block bitmap.sf
- fdc.sf = file descriptor cluster.sf
- pbc.sf = pointer block cluster.sf
- sbc.sf = sub-block cluster.sf
- vh.sf = volume header.sfs
- dd.sf = scsi device description.sf
The VMFS-5 uses one more system file:
- pb2.sf = pointer block 2.sf
Source: [Archive.is] VMFS metadata files