The kernel contains components that control all aspects of retrieving and storing data:
The Index Manager finds and tracks the location of requested data. See Index Manager.
The Allocation Manager, part of the Index Manager, allocates space and manages some file operations. See Allocation Manager.
The Data Block Manager retrieves the data pointed to by the index and stores the data. See Data Block Manager.
The LRO Manager handles retrieval and storage of LROs. See LRO Manager.
The Lock Manager handles the locking of data blocks to regulate concurrent data access. See Lock Manager.
The Transaction Manager tracks transactions and handles internal commit and abort operations. See Transaction Manager.