VFS_GPFS(8) System Administration tools VFS_GPFS(8)
NAME
vfs_gpfs - gpfs specific samba extensions like acls
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 makes use of the smb.conf parameter
acl map full control.
When set to yes (the default), this parameter will add in the
FILE_DELETE_CHILD bit on a returned ACE entry for a file (not a
directory) that already contains all file permissions except for
FILE_DELETE and FILE_DELETE_CHILD. This can prevent Windows
applications that request GENERIC_ALL access from getting
ACCESS_DENIED errors when running against a filesystem with NFSv4
compatible ACLs.
This module is stackable.
Since Samba 4.0 all options are per share options.
OPTIONS
nfs4:mode = [ simple | special ]
Controls substitution of special IDs (OWNER@ and GROUP@) on NFS4
ACLs. The use of mode simple is recommended. In this mode only
non inheriting ACL entries for the file owner and group are
mapped to special IDs.
The following MODEs are understood by the module:
+o simple(default) - use OWNER@ and GROUP@ special IDs
for non inheriting ACEs only.
+o special(deprecated) - use OWNER@ and GROUP@ special
IDs in ACEs for all file owner and group ACEs.
nfs4:acedup = [dontcare|reject|ignore|merge]
This parameter configures how Samba handles duplicate ACEs
encountered in NFS4 ACLs. They allow creating duplicate ACEs with
different bits for same ID, which may confuse the Windows
clients.
Following is the behaviour of Samba for different values :
+o dontcare - copy the ACEs as they come
+o reject (deprecated) - stop operation and exit with
error on ACL set op
+o ignore (deprecated) - don't include the second
matching ACE
+o merge (default) - 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
gpfs:sharemodes = [ yes | no ]
Enable/Disable cross node sharemode handling for GPFS.
+o yes(default) - propagate sharemodes across all GPFS
nodes.
+o no - do not propagate sharemodes across all GPFS
nodes. This should only be used if the GPFS file
system is exclusively exported by Samba. Access by
local unix application or NFS exports could lead to
corrupted files.
gpfs:leases = [ yes | no ]
Enable/Disable cross node leases (oplocks) for GPFS. You should
also set the oplocks and kernel oplocks options to the same
value.
+o yes(default) - propagate leases across all GPFS nodes.
+o no - do not propagate leases across all GPFS nodes.
This should only be used if the GPFS file system is
exclusively exported by Samba. Access by local unix
application or NFS exports could lead to corrupted
files.
gpfs:hsm = [ yes | no ]
Enable/Disable announcing if this FS has HSM enabled.
+o no(default) - Do not announce HSM.
+o yes - Announce HSM.
gpfs:recalls = [ yes | no ]
When this option is set to no, an attempt to open an offline file
will be rejected with access denied. This helps preventing recall
storms triggered by careless applications like Finder and
Explorer.
+o yes(default) - Open files that are offline. This will
recall the files from HSM.
+o no - Reject access to offline files with access
denied. This will prevent recalls of files from HSM.
Using this setting also requires gpfs:hsm to be set to
yes.
gpfs:getrealfilename = [ yes | no ]
Enable/Disable usage of the gpfs_get_realfilename_path()
function. This improves the casesensitive wildcard file name
access.
+o yes(default) - use gpfs_get_realfilename_path().
+o no - do not use gpfs_get_realfilename_path(). It seems
that gpfs_get_realfilename_path() doesn't work on AIX.
gpfs:winattr = [ yes | no ]
Enable/Disable usage of the windows attributes in GPFS. GPFS is
able to store windows file attributes e.g. HIDDEN, READONLY,
SYSTEM and others natively. That means Samba doesn't need to map
them to permission bits or extended attributes.
+o no(default) - do not use GPFS windows attributes.
+o yes - use GPFS windows attributes.
gpfs:acl = [ yes | no ]
This option lets Samba use or ignore GPFS ACLs.
+o yes(default) - use GPFS ACLs.
+o no - do not use GPFS ACLs and pass everything to the
next SMB_VFS module.
gpfs:check_fstype = [ yes | no ]
Check for a mounted GPFS file system on access to a SMB share.
+o yes(default) - Check that the SMB share path is on a
GPFS file system. Share access will be denied when a
different file system is found.
+o no - skip check for GPFS file system on SMB share
path.
gpfs:dfreequota = [ yes | no ]
Adjust reporting of the size and free space of a share according
to quotas. If this setting is "yes", a request for size and free
space will also evaluate the user quota of the user requesting
the data and the group quota of the primary group of the user.
Fileset quotas are not queried, since GPFS already provides the
option --dfreequota to reflect the fileset quota in the free
space query. Please use that option to include fileset quotas in
the reported disk space.
If any of the soft or hard quota limits has been reached, the
free space will be reported as 0. If a quota is in place, but the
limits have not been reached, the free space will be reported
according to the space left in the quota. If more than one quota
applies the free space will be reported as the smallest space
left in those quotas. The size of the share will be reported
according to the quota usage. If more than one quota applies, the
smallest size will be reported for the share size according to
these quotas.
+o yes - include the quotas when reporting the share size
and free space
+o no(default) - do not include quotas, simply report the
size and free space of the file system
gpfs:settimes = [ yes | no ]
Use the gpfs_set_times API when changing the timestamps of a file
or directory. If the GPFS API is not available the old method of
using utime and the GPFS winattr call will be used instead.
+o yes(default) - Use gpfs_set_times. Fall back to utime
and winattr when it is not available.
+o no - Do not use gpfs_set_times.
gpfs:syncio = [yes|no]
This parameter makes Samba open all files with O_SYNC. This
triggers optimizations in GPFS for workloads that heavily share
files.
Following is the behaviour of Samba for different values:
+o yes - Open files with O_SYNC
+o no (default) - Open files as normal Samba would do
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 = mergeCAVEATS
Depending on the version of gpfs, the libgpfs_gpl library or the
libgpfs library is needed at runtime by the gpfs VFS module: Starting
with gpfs 3.2.1 PTF8, the complete libgpfs is available as open
source and libgpfs_gpl does no longer exist. With earlier versions of
gpfs, only the libgpfs_gpl library was open source and could be used
at run time.
At build time, only the header file gpfs_gpl.h is required, which is
a symlink to gpfs.h in gpfs versions newer than 3.2.1 PTF8.
VERSION
This man page is part of version 4.18.11 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 4.18.11 03/13/2024 VFS_GPFS(8)
