1VFS_GPFS(8)               System Administration tools              VFS_GPFS(8)
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NAME

6       vfs_gpfs - gpfs specific samba extensions like acls and prealloc
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SYNOPSIS

9       vfs objects = gpfs
10

DESCRIPTION

12       This VFS module is part of the samba(7) suite.
13
14       The gpfs VFS module is the home for all gpfs extensions that Samba
15       requires for proper integration with GPFS. It uses the GPL library
16       interfaces provided by GPFS.
17
18       Currently the gpfs vfs module provides extensions in following areas :
19
20              ·   NFSv4 ACL Interfaces with configurable options for GPFS
21
22              ·   Kernel oplock support on GPFS
23
24              ·   Lease support on GPFS
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26
27       NOTE: This module follows the posix-acl behaviour and hence allows
28       permission stealing via chown. Samba might allow at a later point in
29       time, to restrict the chown via this module as such restrictions are
30       the responsibility of the underlying filesystem than of Samba.
31
32       This module makes use of the smb.conf parameter acl map full control.
33       When set to yes (the default), this parameter will add in the
34       FILE_DELETE_CHILD bit on a returned ACE entry for a file (not a
35       directory) that already contains all file permissions except for
36       FILE_DELETE and FILE_DELETE_CHILD. This can prevent Windows
37       applications that request GENERIC_ALL access from getting ACCESS_DENIED
38       errors when running against a filesystem with NFSv4 compatible ACLs.
39
40       This module is stackable.
41
42       Since Samba 4.0 all options are per share options.
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OPTIONS

45       gpfs:sharemodes = [ yes | no ]
46           Enable/Disable cross node sharemode handling for GPFS.
47
48                  ·   yes(default) - propagate sharemodes across all GPFS
49                      nodes.
50
51                  ·   no - do not propagate sharemodes across all GPFS nodes.
52                      This should only be used if the GPFS file system is
53                      exclusively exported by Samba. Access by local unix
54                      application or NFS exports could lead to corrupted
55                      files.
56
57
58       gpfs:leases = [ yes | no ]
59           Enable/Disable cross node leases (oplocks) for GPFS. You should
60           also set the oplocks and kernel oplocks options to the same value.
61
62                  ·   yes(default) - propagate leases across all GPFS nodes.
63
64                  ·   no - do not propagate leases across all GPFS nodes. This
65                      should only be used if the GPFS file system is
66                      exclusively exported by Samba. Access by local unix
67                      application or NFS exports could lead to corrupted
68                      files.
69
70
71       gpfs:hsm = [ yes | no ]
72           Enable/Disable announcing if this FS has HSM enabled.
73
74                  ·   no(default) - Do not announce HSM.
75
76                  ·   yes - Announce HSM.
77
78
79       gpfs:recalls = [ yes | no ]
80           When this option is set to no, an attempt to open an offline file
81           will be rejected with access denied. This helps preventing recall
82           storms triggered by careless applications like Finder and Explorer.
83
84                  ·   yes(default) - Open files that are offline. This will
85                      recall the files from HSM.
86
87                  ·   no - Reject access to offline files with access denied.
88                      This will prevent recalls of files from HSM. Using this
89                      setting also requires gpfs:hsm to be set to yes.
90
91
92       gpfs:getrealfilename = [ yes | no ]
93           Enable/Disable usage of the gpfs_get_realfilename_path() function.
94           This improves the casesensitive wildcard file name access.
95
96                  ·   yes(default) - use gpfs_get_realfilename_path().
97
98                  ·   no - do not use gpfs_get_realfilename_path(). It seems
99                      that gpfs_get_realfilename_path() doesn't work on AIX.
100
101
102       gpfs:winattr = [ yes | no ]
103           Enable/Disable usage of the windows attributes in GPFS. GPFS is
104           able to store windows file attributes e.g. HIDDEN, READONLY, SYSTEM
105           and others natively. That means Samba doesn't need to map them to
106           permission bits or extended attributes.
107
108                  ·   no(default) - do not use GPFS windows attributes.
109
110                  ·   yes - use GPFS windows attributes.
111
112
113       gpfs:merge_writeappend = [ yes | no ]
114           GPFS ACLs doesn't know about the 'APPEND' right. This option lets
115           Samba map the 'APPEND' right to 'WRITE'.
116
117                  ·   yes(default) - map 'APPEND' to 'WRITE'.
118
119                  ·   no - do not map 'APPEND' to 'WRITE'.
120
121
122       gpfs:acl = [ yes | no ]
123           This option lets Samba use or ignore GPFS ACLs.
124
125                  ·   yes(default) - use GPFS ACLs.
126
127                  ·   no - do not use GPFS ACLs and pass everything to the
128                      next SMB_VFS module.
129
130
131       gpfs:refuse_dacl_protected = [ yes | no ]
132           As GPFS does not support the ACE4_FLAG_NO_PROPAGATE NFSv4 flag
133           (which would be the mapping for the DESC_DACL_PROTECTED flag), the
134           status of this flag is currently silently ignored by Samba. That
135           means that if you deselect the "Allow inheritable permissions..."
136           checkbox in Windows' ACL dialog and then apply the ACL, the flag
137           will be back immediately.
138
139           To make sure that automatic migration with e.g. robocopy does not
140           lead to ACLs silently (and unintentionally) changed, you can set
141           gpfs:refuse_dacl_protected = yes to enable an explicit check for
142           this flag and if set, it will return NT_STATUS_NOT_SUPPORTED so
143           errors are shown up on the Windows side and the Administrator is
144           aware of the ACLs not being settable like intended
145
146                  ·   no(default) - ignore the DESC_DACL_PROTECTED flags.
147
148                  ·   yes - reject ACLs with DESC_DACL_PROTECTED.
149
150
151       gpfs:dfreequota = [ yes | no ]
152           Adjust reporting of the size and free space of a share according to
153           quotas. If this setting is "yes", a request for size and free space
154           will also evaluate the user quota of the user requesting the data
155           and the group quota of the primary group of the user. Fileset
156           quotas are not queried, since GPFS already provides the option
157           --dfreequota to reflect the fileset quota in the free space query.
158           Please use that option to include fileset quotas in the reported
159           disk space.
160
161           If any of the soft or hard quota limits has been reached, the free
162           space will be reported as 0. If a quota is in place, but the limits
163           have not been reached, the free space will be reported according to
164           the space left in the quota. If more than one quota applies the
165           free space will be reported as the smallest space left in those
166           quotas. The size of the share will be reported according to the
167           quota usage. If more than one quota applies, the smallest size will
168           be reported for the share size according to these quotas.
169
170                  ·   yes - include the quotas when reporting the share size
171                      and free space
172
173                  ·   no(default) - do not include quotas, simply report the
174                      size and free space of the file system
175
176
177       gpfs:prealloc = [ yes | no ]
178           If set to yes the gpfs_prealloc function will be used in the
179           fallocate callback when appropriate. If set to no gpfs_prealloc
180           will not be used. In both cases the system and libc calls are
181           avoided.
182
183                  ·   yes (default) - Use gpfs_prealloc for the fallocate
184                      callback.
185
186                  ·   no - Do not use gpfs_prealloc for the fallocate
187                      callback.
188
189
190       gpfs:settimes = [ yes | no ]
191           Use the gpfs_set_times API when changing the timestamps of a file
192           or directory. If the GPFS API is not available the old method of
193           using utime and the GPFS winattr call will be used instead.
194
195                  ·   yes(default) - Use gpfs_set_times. Fall back to utime
196                      and winattr when it is not available.
197
198                  ·   no - Do not use gpfs_set_times.
199
200
201       nfs4:mode = [ simple | special ]
202           Controls substitution of special IDs (OWNER@ and GROUP@) on GPFS.
203           The use of mode simple is recommended. In this mode only non
204           inheriting ACL entries for the file owner and group are mapped to
205           special IDs.
206
207           The following MODEs are understood by the module:
208
209                  ·   simple(default) - use OWNER@ and GROUP@ special IDs for
210                      non inheriting ACEs only.
211
212                  ·   special(deprecated) - use OWNER@ and GROUP@ special IDs
213                      in ACEs for all file owner and group ACEs.
214
215
216       nfs4:acedup = [dontcare|reject|ignore|merge]
217           This parameter configures how Samba handles duplicate ACEs
218           encountered in GPFS ACLs. GPFS allows/creates duplicate ACE for
219           different bits for same ID.
220
221           Following is the behaviour of Samba for different values :
222
223                  ·   dontcare (default) - copy the ACEs as they come
224
225                  ·   reject - stop operation and exit with error on ACL set
226                      op
227
228                  ·   ignore - don't include the second matching ACE
229
230                  ·   merge - bitwise OR the 2 ace.flag fields and 2 ace.mask
231                      fields of the 2 duplicate ACEs into 1 ACE
232
233
234       nfs4:chown = [yes|no]
235           This parameter allows enabling or disabling the chown supported by
236           the underlying filesystem. This parameter should be enabled with
237           care as it might leave your system insecure.
238
239           Some filesystems allow chown as a) giving b) stealing. It is the
240           latter that is considered a risk.
241
242           Following is the behaviour of Samba for different values :
243
244                  ·   yes - Enable chown if as supported by the under
245                      filesystem
246
247                  ·   no (default) - Disable chown
248
249
250       gpfs:syncio = [yes|no]
251           This parameter makes Samba open all files with O_SYNC. This
252           triggers optimizations in GPFS for workloads that heavily share
253           files.
254
255           Following is the behaviour of Samba for different values:
256
257                  ·   yes - Open files with O_SYNC
258
259                  ·   no (default) - Open files as normal Samba would do
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261

EXAMPLES

263       A GPFS mount can be exported via Samba as follows :
264
265                   [samba_gpfs_share]
266                vfs objects = gpfs
267                path = /test/gpfs_mount
268                nfs4: mode = special
269                nfs4: acedup = merge
270

CAVEATS

272       Depending on the version of gpfs, the libgpfs_gpl library or the
273       libgpfs library is needed at runtime by the gpfs VFS module: Starting
274       with gpfs 3.2.1 PTF8, the complete libgpfs is available as open source
275       and libgpfs_gpl does no longer exist. With earlier versions of gpfs,
276       only the libgpfs_gpl library was open source and could be used at run
277       time.
278
279       At build time, only the header file gpfs_gpl.h is required, which is a
280       symlink to gpfs.h in gpfs versions newer than 3.2.1 PTF8.
281

VERSION

283       This man page is part of version 4.8.3 of the Samba suite.
284

AUTHOR

286       The original Samba software and related utilities were created by
287       Andrew Tridgell. Samba is now developed by the Samba Team as an Open
288       Source project similar to the way the Linux kernel is developed.
289
290       The GPFS VFS module was created with contributions from Volker Lendecke
291       and the developers at IBM.
292
293       This manpage was created by the IBM FSCC team
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297Samba 4.8.3                       10/30/2018                       VFS_GPFS(8)
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