GPFS: Administration and Programming Reference - IRA Home

This ACL shows four ACL entries (an allow and deny entry for each of owner@ and guest).
In general, constructing NFS V4 ACLs is more complicated than traditional ACLs. Users new to NFS V4
ACLs may find it useful to start with a traditional ACL and allow either mmgetacl or mmeditacl to provide
the NFS V4 translation, using the -k nfs4 flag as a starting point when creating an ACL for a new file.
Displaying NFS V4 access control lists
The mmgetacl command displays an existing ACL regardless of its type (traditional or NFS V4). The
format of the ACL that is returned depends on the file system setting (-k flag), as well as the format of the
actual ACL associated with the file. For details, see “NFS V4 ACL translation” on page 50.
Applying an existing NFS V4 access control lists
This function is identical, whether using traditional or NFS V4 ACLs. See “Applying an existing traditional
GPFS access control list” on page 47.
Changing NFS V4 access control lists
This function is identical, whether using traditional or NFS V4 ACLs. See “Changing traditional GPFS
access control lists” on page 48.
Deleting NFS V4 access control lists
Use the mmdelacl command to delete NFS V4 ACLs. Once the ACL has been deleted, permissions revert
to the mode bits. If the mmgetacl command is then used to display the ACL (mmgetacl -k native), it
appears as a traditional GPFS ACL.
When assigning an ACL to a file that already has an NFS V4 ACL, there are some NFS rules that must be
followed. Specifically, in the case of a directory, there will not be two separate (access and default) ACLs,
as there are with traditional ACLs. NFS V4 requires a single ACL entity and allows individual ACL entries
to be flagged if they are to be inherited. Consequently, mmputacl -d is not allowed if the existing ACL was
the NFS V4 type, since this attempts to change only the default ACL. Likewise mmputacl (without the -d
flag) is not allowed because it attempts to change only the access ACL, leaving the default unchanged. To
change such an ACL, use the mmeditacl command to change the entire ACL as a unit. Alternatively, use
the mmdelacl command to remove an NFS V4 ACL, followed by the mmputacl command.
GPFS exceptions and limitations to NFS V4 ACLs
For a list of GPFS exceptions and limitations with NFS V4 ACLs, see “GPFS exceptions and limitations to
NFS V4 ACLs” on page 372.
NFS and GPFS
®
GPFS file systems may be exported using the Network File System (NFS ) protocol from one or more
nodes. After export, normal access to the file system may proceed from GPFS cluster nodes or NFS client
nodes.
Considerations for the interoperability of a GPFS file system include:
v “Exporting a GPFS file system using NFS”
v “NFS usage of GPFS cache” on page 54
v “Synchronous writing using NFS” on page 55
v “Unmounting a file system after NFS export” on page 55
v “NIS automount considerations” on page 55
Exporting a GPFS file system using NFS
To export a GPFS file system:
52 GPFS: Administration and Programming Reference