VFS_GPFS(8) System Administration tools VFS_GPFS(8)NAMEvfs_gpfs - gpfs specific samba extensions like acls and prealloc
SYNOPSIS
vfs objects = gpfs
DESCRIPTION
This VFS module is part of the samba(7) suite.
The gpfs VFS module is the home for all gpfs extensions that Samba
requires for proper integration with GPFS. It uses the GPL library
interfaces provided by GPFS.
Currently the gpfs vfs module provides extensions in following areas :
o NFSv4 ACL Interfaces with configurable options for GPFS
o Kernel oplock support on GPFS
o Lease support on GPFS
NOTE:This module follows the posix-acl behaviour and hence allows
permission stealing via chown. Samba might allow at a later point in
time, to restrict the chown via this module as such restrictions are
the responsibility of the underlying filesystem than of Samba.
This module is stackable.
OPTIONS
nfs4:mode = [ simple | special ]
Enable/Disable substitution of special IDs on GPFS. This parameter
should not affect the windows users in anyway. It only ensures that
Samba sets the special IDs - OWNER@ and GROUP@ ( mappings to simple
uids ) that are relevant to GPFS.
The following MODEs are understood by the module:
o simple(default) - do not use special IDs in GPFS ACEs
o special - use special IDs in GPFS ACEs.
nfs4:acedup = [dontcare|reject|ignore|merge]
This parameter configures how Samba handles duplicate ACEs
encountered in GPFS ACLs. GPFS allows/creates duplicate ACE for
different bits for same ID.
Following is the behaviour of Samba for different values :
o dontcare (default) - copy the ACEs as they come
o reject - stop operation and exit with error on ACL set op
o ignore - don't include the second matching ACE
o merge - bitwise OR the 2 ace.flag fields and 2 ace.mask fields
of the 2 duplicate ACEs into 1 ACE
nfs4:chown = [yes|no]
This parameter allows enabling or disabling the chown supported by
the underlying filesystem. This parameter should be enabled with
care as it might leave your system insecure.
Some filesystems allow chown as a) giving b) stealing. It is the
latter that is considered a risk.
Following is the behaviour of Samba for different values :
o yes - Enable chown if as supported by the under filesystem
o no (default) - Disable chown
EXAMPLES
A GPFS mount can be exported via Samba as follows :
[samba_gpfs_share]
vfs objects = gpfs
path = /test/gpfs_mount
nfs4: mode = special
nfs4: acedup = merge
CAVEATS
The gpfs gpl libraries are required by gpfs VFS module during both
compilation and runtime. Also this VFS module is tested to work on SLES
9/10 and RHEL 4.4
VERSION
This man page is correct for version 3.0.25 of the Samba suite.
AUTHOR
The original Samba software and related utilities were created by
Andrew Tridgell. Samba is now developed by the Samba Team as an Open
Source project similar to the way the Linux kernel is developed.
The GPFS VFS module was created with contributions from Volker Lendecke
and the developers at IBM.
This manpage was created by the IBM FSCC team
Samba 3.0 05/28/2008 VFS_GPFS(8)
