Optimizing NFS directory access for CIFS clients

About NFS directory accessibility

When you first install Data ONTAP, directories created by NFS clients are created in non-Unicode format and directories created by CIFS clients are in Unicode format. Because of this, CIFS directories are directly accessible to NFS clients, but NFS directories are not directly accessible to CIFS clients. To provide a CIFS client with access to an NFS directory, the filer must first convert the NFS directory to Unicode format. This is done automatically ("on the fly"), as the filer receives the access request. Depending on the amount of data involved, Unicode conversion can take time and consume filer resources.

Optimizing CIFS client access to an NFS directory

You can optimize CIFS client access to an NFS directory by performing the following tasks to reduce or eliminate latency caused by converting an NFS directory format conversion:

Configure Data ONTAP to convert non-Unicode directories to Unicode format when either CIFS clients or NFS clients access directories.
Change Data ONTAP to create only Unicode-formatted directories, thereby eliminating the need to convert formats.
Note
If you intend to share files between CIFS and NFS clients, configure Data ONTAP to create directories in Unicode format immediately after installing Data ONTAP. This will to ensure that all new directories are created in Unicode format.

Creating Unicode-formatted directories

To cause Data ONTAP to create all directories in Unicode format, complete the following step.

Step	Action
1	Enter the following command: *vol options volume_name* create_ucode on**

Converting to Unicode format

By default, Data ONTAP performs Unicode conversion of a directory only when a CIFS client requests access. You can reduce the time required for Unicode conversion by limiting the number of entries in each directory to less than 50,000.

Once you already have large directories, you can minimize the performance impact of Unicode conversion by preemptively forcing Unicode conversion for large directories as described in the procedure below.

To force Unicode conversion of large directories and to convert directories to Unicode format when they are accessed from both CIFS and NFS clients, complete the following steps.

Step	Action
1	If...	Then...
	You have a directory that contains more than 50,000 files	Create a new CIFS directory from a Windows client on the same volume and in the same qtree as the directory you want to convert. Use the NFS `mv` command to move the files into the directory you just created. Optionally remove the old directory and assign its name to the new directory. Go on to Step 2, below.



	You have directories that contain fewer than 50,000 files	Go to Step 2.
2	Enter the following command: vol options volume_name convert_ucode on Result Unicode conversion is performed when NFS clients access files.

Note
Do not enable the convert_ucode option when you have directories that contain more than 50,000 files.

Optimizing NFS directory access for CIFS clients

About NFS directory accessibility

Optimizing CIFS client access to an NFS directory

Creating Unicode-formatted directories

Converting to Unicode format

Result