4. File storage space management
mind Mapping
File initialization and division
The physical disk is divided into multiple file volumes. The
file volume is divided into a directory area and a file area.
File area: store file data.
Directory area: store file directory information (FCB) and information used for disk storage space management
File storage space management method
1. Storage space management-free list method
Use a table to record the free blocks in the disk, space recovery and allocation only need to operate on the table
2. Storage space management-free linked list method
Free disk block chain:
Free disk block chain:
3. Storage space management-bitmap method
A bitmap is used to record the idle state of each physical block, and allocation and recovery are performed on the bitmap
4. Storage space management-group link method
Super block
The group link method must have a super block, as the head pointer of all physical blocks of the hard disk, pointing to the next group of free disk blocks.
distribution:
Recycling:
