How big is the inode table in ext2?
Inodes have a fixed size of either 128 for version 0 Ext2 file systems, or as dictated by the field in the Superblock for version 1 file systems. All inodes reside in inode tables that belong to block groups. Therefore, looking up an inode is simply a matter of determining which block group it belongs to and indexing that block group’s inode table.
How are the size of blocks determined in ext2?
The Ext2 file system divides up disk space into logical blocks of contiguous space. The size of blocks need not be the same size as the sector size of the disk the file system resides on. The size of blocks can be determined by reading the field starting at byte 24 in the Superblock . What is a Block Group?
What are the reserved inodes in ext2 osdev?
With Ext2 versions prior to Major version 1, inodes 1 to 10 are reserved and should be in an allocated state. Starting with version 1, the first non-reserved inode is indicated via a field in the Superblock. Of the reserved inodes, number 2 subjectively has the most significance as it is used for the root directory.
Where does the superblock begin in osdev 2?
For example, if the disk uses 512 byte sectors, the Superblock will begin at LBA 2 and will occupy all of sector 2 and 3. From the Superblock, extract the size of each block, the total number of inodes, the total number of blocks, the number of blocks per block group, and the number of inodes in each block group.
What does an inode on a disk represent?
An inode is a structure on the disk that represents a file, directory, symbolic link, etc. Inodes do not contain the data of the file / directory / etc. that they represent. Instead, they link to the blocks that actually contain the data.
How does the ext2 file system divide up disk space?
The Ext2 file system divides up disk space into logical blocks of contiguous space. The size of blocks need not be the same size as the sector size of the disk the file system resides on.