HP CIFS Opportunistic Locking Usage Guidelines

6
1 open file
2 client cache file locally
[share]
oplocks = yes
4 open request
6 flush file to server
3
reads
writes
local cache
5 oplock break
7
shared access
shared access
Client 1
Client 2
CIFS/9000 Server
1. Client 1 opens file on CIFS/9000 Server share. Client has exclusive access to file (no
other processes are accessing the file). Exclusive access is not an access mode (like
DENY_ALL) – it is an access state.
2. Client 1caches the file locally.
3. Client 1 performs reads, writes, and locks locally, thereby reducing network latency
for these operations.
4. Client 2 sends an open request to the CIFS/9000 Server for the file that Client 1 is
working on. The file open is blocked.
5. The CIFS/9000 Server sends an oplock break to client 1
6. Client 1 then sends the file with all of the applied changes back to the CIFS/9000
Server
7. After the server receives the file from client 1 and writes the changes to disk, it
allows concurrent file access by Client 1 and Client 2, as dictated by the file open
properties of each opening process. Now all operations are performed over the
network.