level2 oplocks (S) This parameter controls whether Samba supports level2 (read-only) oplocks on a share. Level2, or read-only oplocks allow Windows NT clients that have an oplock on a file to downgrade from a read-write oplock to a read-only oplock once a second client opens the file (instead of releasing all oplocks on a second open, as in traditional, exclusive oplocks). This allows all openers of the file that support level2 oplocks to cache the file for read-ahead only (ie. they may not cache writes or lock requests) and increases performance for many accesses of files that are not commonly written (such as application .EXE files). Once one of the clients which have a read-only oplock writes to the file all clients are notified (no reply is needed or waited for) and told to break their oplocks to "none" and delete any read-ahead caches. It is recommended that this parameter be turned on to speed access to shared executables. For more discussions on level2 oplocks see the CIFS spec. Currently, if kernel oplocks are supported then level2 oplocks are not granted (even if this parameter is set to yes). Note also, the oplocks parameter must be set to yes on this share in order for this parameter to have any effect. See also the oplocks and kernel oplocks parameters. Default: level2 oplocks = yes