Exam 350-601 topic 1 question 180 discussion

C => NFSv4

NFSv4's implementation of a lease-based locking mechanism distinguishes it from other protocols. This design reduces the overhead associated with file locks, enhances consistency, and improves overall performance in distributed file systems. Therefore, NFSv4 is the protocol that reduces file locks by using leasing.

With the NFS version 4 protocol, the support for file locking is part of the NFS protocol. The file locking support is structured so that an RPC callback mechanism is not required. This is a departure from the previous versions of the NFS file locking protocol, Network Lock Manager (NLM). The state associated with file locks is maintained at the server under a lease-based model. https://www.ibm.com/docs/en/zos/2.3.0?topic=control-locking-in-nfs-version-4

CIFS (Common Internet File System) and SMB (Server Message Block) are both Windows file-sharing protocols used in storage systems, such as network-attached systems (NAS). The key difference between CIFS and SMB is that CIFS is a dialect of SMB – a particular implementation of the SMB protocol correct answer is C

SMB Directory Leasing For branch office users connecting over WAN networks with high latencies, reducing the number of round-trips between a client and a server dramatically improves application response times. Directory Leasing is an enhancement to the existing SMB protocol that reduces the number of round-trips between client and server. With Directory Leasing, client computers request a lease lock on directory information (which contains the file metadata), enabling Windows to cache the information for longer periods. Because many end-user applications access file metadata frequently, caching it for longer periods reduces the round-trips that a client has to wait for, improving the application response time.

I agree with skjs and others, the correct answer is C.

A is the one!

Answer is A: The question is about reducing file locks, not which protocol uses file locks, SMB has directory leasing for it. As explained in the link from crosillo30

Its about file locks (NFS v4) not directory locks(SMB) C

I think shoul be letter A: Reference: https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2012-R2-and-2012/hh831495(v=ws.11)#:~:text=Directory%20Leasing%20is%20an%20enhancement%20to%20the%20existing,Windows%20to%20cache%20the%20information%20for%20longer%20periods.