• Configure a file system for multiprotocol file sharing

    PDF

    Configure a file system for multiprotocol file sharing

    Create a file system

    Before you begin

    Make sure there is a NAS server configured to support multiprotocol, and that a pool exists with enough available storage space.

    Procedure
    1. Under Storage, select File > File Systems.
    2. Select the Add icon.
    3. On the Protocol window, select Multiprotocol Shares (SMB and NFS). Then select the associated NAS server.
    4. Optionally click Advanced to select advanced SMB settings, and customize the file system's access, folder rename, and locking policies.
    5. Continue following the steps in the wizard while noting the following:
      • On the Storage page, the Thin checkbox is selected by default. If you do not want to create a thin file system, remove the checkmark from the Thin checkbox. Removing the checkmark also disables the Compression option.
      • On the Storage page, select the Compression checkbox to enable compression on the file system. Compression occurs only to data written to the file system after enabling compression. Existing file system data is not compressed. Compression can be enabled only on thin file systems that reside in all-Flash pools, and only for thin file systems created on Unity systems running OE version 4.2.x or later.
      • On the Shares page, optionally configure the initial share for the file system. For a multiprotocol file system, you can create an NFS share and an SMB share simultaneously. These shares will have the same name and description.
      • You can configure host access and a snapshot schedule for the file system when you create the file system, or you can do this at a later time.

    Advanced SMB file system settings

    You can set these advanced settings when you change the configuration of an existing SMB-enabled or multiprotocol-enabled file system.

    Setting
    Description
    Sync Writes Enabled
    When you enable the synchronous writes option for a Windows (SMB) or multiprotocol file system, the storage system performs immediate synchronous writes for storage operations, regardless of how the SMB protocol performs write operations. Enabling synchronous writes operations allow you to store and access database files (for example, MySQL) on storage system SMB shares. This option guarantees that any write to the share is done synchronously and reduces the chances of data loss or file corruption in various failure scenarios, for example, loss of power.

    This option is disabled by default.

    The synchronous writes option can have a big impact on performance. It is not recommended unless you intend to use Windows file systems to provide storage for database applications.
    Oplocks Enabled
    (Enabled by default) Opportunistic file locks (oplocks) allow SMB clients to buffer file data locally before sending it to a server. SMB clients can then work with files locally and periodically communicate changes to the storage system rather than having to communicate every operation over the network to the storage system. This feature is enabled by default for Windows (SMB) and multiprotocol file systems. Unless your application handles critical data or has specific requirements that make this mode or operation unfeasible, leaving the oplocks enabled is recommended.

    The following oplocks implementations are supported:

    • Level II oplocks, which informs a client that multiple clients are currently accessing a file, but no client has yet modified it. A level II oplock lets the client perform read operations and file attribute fetches by using cached or read-ahead local information. All other file access requests must be sent to the server.
    • Exclusive oplocks, which informs a client that it is the only client opening the file. An exclusive oplock lets a client perform all file operations by using cached or read-ahead information until it closes the file, at which time the server must be updated with any changes made to the state of the file (contents and attributes).
    • Batch oplocks, which informs a client that it is the only client opening the file. A batch oplock lets a client perform all file operations by using cached or read-ahead information (including opens and closes). The server can keep a file opened for a client even though the local process on the client machine has closed the file. This mechanism curtails the amount of network traffic by letting clients skip the extraneous close and open requests.
    Notify on Write Enabled
    Enable notification when a file system is written to.

    This option is disabled by default.

    Notify on Access Enabled
    Enable notification when a file system is accessed.

    This option is disabled by default.

    Enable SMB Events publishing
    Enable the processing of SMB events for this file system.

    Multiprotocol file system security settings

    Unity offers the ability to customize the access, rename, and locking policies for a multiprotocol file system.

    File system access policies

    You can select one of the following access policies for a multiprotocol file system:

    • Native Security
    • UNIX Security
    • Windows Security

    For information about these access policies, see Access policies for NFS, SMB, and FTP.

    File system rename policies

    You can select one of the following rename policies for a multiprotocol file system. This policy controls the circumstances under which NFS and SMB clients can rename a directory. Value is one of the following:

    Setting
    Description
    Allowed
    All NFS and SMB clients can rename directories without any restrictions.
    SMB
    (Default) Only NFS clients can rename directories without any restrictions. An SMB client cannot rename a directory in the path if at least one file is opened in the directory or in one of its subdirectories. For example, if the path to a file is C:\Dir1\Dir2\Dir3\File1.txt, and an SMB client opens File1, neither Dir1, Dir2 , or Dir3 can be renamed.
    Not Allowed
    NFS and SMB clients cannot rename a directory if at least one file is opened in the directory or in one of its subdirectories.
    File system locking policies

    SMB and NFS have their own lock range. Protocol specifications define lock ranges as mandatory for SMB but may be advisory for NFS. NFSv3/v3 uses a separate protocol (NLM) that is always advisory. NFSv4 has the lock management integrated in the protocol itself, but may also be advisory or mandatory, depending of the implementation.

    A locking policy property is used to define the alternate behavior. You can select one of the following locking policies for a multiprotocol file system:

    Setting
    Description
    Mandatory
    (Default) Uses the SMB and NFSv4 protocols to manage range locks for a file that is in use by another user. A mandatory locking policy prevents data corruption if there is concurrent access to the same locked data.
    Advisory
    In response to lock requests, reports that there is a range lock conflict, but does not prevent access to the file. This policy allows NFSv3 applications that are not range-lock compliant to continue working, but risks data corruption if there are concurrent writes.