Accessing CIFS files from NFS clients

How NFS clients access CIFS files

Data ONTAP uses Windows NT File System (NTFS) security semantics to determine whether a UNIX user, on an NFS client, has access to a file in a mixed or NTFS qtree. Data ONTAP does this by converting the user's UNIX User ID (UID) into a CIFS credential, then using the CIFS credential to verify that the user has access rights to the file. A CIFS credential consists of a primary Security Identifier (SID), usually the user's Windows NT user name, and one or more group SIDs that correspond to Windows NT groups of which the user is a member.

The time Data ONTAP takes converting the UNIX UID into a CIFS credential can be from tens of milliseconds to hundreds of milliseconds because the process involves contacting a domain controller. Data ONTAP maps the UID to the CIFS credential and enters the mapping in a WAFL credential cache to reduce the verification time caused by the conversion. You can control the WAFL credential cache to further reduce the time Data ONTAP takes to verify rights. You can also monitor WAFL credential cache statistics to help you determine what CIFS credentials are currently in the WAFL credential cache.

For detailed information

The following sections discuss tasks you can perform to manage the WAFL credential cache: