Why Does Oracle Delete redolog on Linux still work properly?

When performing a redolog loss recovery test, you can delete Oracle redolog in the open Database state, and the database still works normally. The database can perform regular operations, or even create tablespaces, perform log switching, and execute checkpoints. Only errors that do not exist in redolog are reported during archiving.

Very strange.

In the past, this was related to the file management mechanism of the Linux system: as long as a process is connected, the file will not be deleted when RM is executed, but only an identifier is added, the original information is retained in the memory. It is deleted only when all processes are disconnected. If you use the sync command to synchronize the memory information with the disk, Oracle will halt there.