HP UX Common Internet File System (CIFS) Client/Server Software manual EMC Celerra

8.2EMC Celerra

EMC markets its Celerra file server as a NAS front-end to a Symetrix disk array. Celerra is a single-purpose front-end server used exclusively for storage access to Symetrix. It runs a proprietary OS called DART that is incapable of running applications, users, or accessing and interoperating with non -EMC storage devices.

Since Celerra supports no users or applications, UNIX-Windows concurrent file access is not an issue. EMC documentation about locking behavior of Celerra is vague, but basic behavior can be surmised by utilizing various documents.

Based upon EMC documentation, Celerra provides the following file locking ability:

Mandatory Share Mode (Open Mode)	EMC Celerra
Lock Windows	Yes
Lock UNIX – no advisory locking	Not Applicable
Lock UNIX – advisory locking	Not Applicable
Lock UNIX/NFS – no advisory locking	Unknown12
Lock UNIX/NFS – advisory locking	Yes
Lock PC-NFS	Unknown
Byte Range Locking
Lock Windows	Yes
Lock UNIX – no advisory locking	Not Applicable
Lock UNIX – advisory locking	Not Applicable
Lock UNIX/NFS – no advisory locking	Unknown12
Lock UNIX/NFS – advisory locking	Yes
Lock PC-NFS	Unknown
Oplocks
Break Oplock for Windows access	Yes
Break Oplock for UNIX access – no	Not Applicable
advisory
Break Oplock for UNIX access - advisory	Not Applicable
Break Oplock for UNIX/NFS – no advisory	Unknown
Break Oplock for UNIX/NFS – advisory	Unknown
Break Oplock for PC-NFS	Unknown

EMC Celerra appears to provide Mandatory Share Mode (open mode) locking for concurrent access with UNIX/NFS when the advisory locking protocol is adhered to. They make no statement about PC-NFS. CIFS/9000 provides this locking feature at the HP-UX September 2001 Application Release.

EMC Celerra appears to provide byte range locking for UNIX/NFS when the advisory locking protocol is adhered to. They make no statement about PC-NFS. CIFS/9000 provides byte range locking for UNIX, UNIX/NFS and PC-NFS.

12 Anecdotal evidence suggests Celerra has this feature. See Appendix B.5

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