path: root/docs-xml/manpages-3/vfs_gpfs.8.xml

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<!DOCTYPE refentry PUBLIC "-//Samba-Team//DTD DocBook V4.2-Based Variant V1.0//EN" "http://www.samba.org/samba/DTD/samba-doc">
<refentry id="vfs_gpfs.8">

<refmeta>
	<refentrytitle>vfs_gpfs</refentrytitle>
	<manvolnum>8</manvolnum>
	<refmiscinfo class="source">Samba</refmiscinfo>
	<refmiscinfo class="manual">System Administration tools</refmiscinfo>
	<refmiscinfo class="version">3.6</refmiscinfo>
</refmeta>


<refnamediv>
	<refname>vfs_gpfs</refname>
	<refpurpose>gpfs specific samba extensions like acls and prealloc</refpurpose>
</refnamediv>

<refsynopsisdiv>
	<cmdsynopsis>
		<command>vfs objects = gpfs</command>
	</cmdsynopsis>
</refsynopsisdiv>

<refsect1>
	<title>DESCRIPTION</title>

	<para>This VFS module is part of the
	<citerefentry><refentrytitle>samba</refentrytitle>
	<manvolnum>7</manvolnum></citerefentry> suite.</para>

	<para>The <command>gpfs</command> 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.
	</para>

	<para>Currently the gpfs vfs module provides extensions in following areas :
	<itemizedlist>
	<listitem><para>NFSv4 ACL Interfaces with configurable options for GPFS</para></listitem>
	<listitem><para>Kernel oplock support on GPFS</para></listitem>
	<listitem><para>Lease support on GPFS</para></listitem>
	</itemizedlist>
	</para>

	<para><command>NOTE:</command>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.
	</para>

	<para>This module is stackable.</para>

</refsect1>


<refsect1>
	<title>OPTIONS</title>

	<variablelist>

		<varlistentry>

		<term>gpfs:sharemodes = [ yes | no ]</term>
		<listitem>
		<para>
		Enable/Disable cross node sharemode handling for GPFS.
		</para>

		<itemizedlist>
		<listitem><para>
		<command>yes(default)</command> - propagate sharemodes across all GPFS nodes.
		</para></listitem>
		<listitem><para>
		<command>no</command> - 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.
		</para></listitem>
		</itemizedlist>
		</listitem>

		</varlistentry>
		<varlistentry>

		<term>gpfs:leases = [ yes | no ]</term>
		<listitem>
		<para>
		Enable/Disable cross node leases (oplocks) for GPFS.
		You should also set the <command>oplocks</command> and <command>kernel oplocks</command>
		options to the same value.
		</para>

		<itemizedlist>
		<listitem><para>
		<command>yes(default)</command> - propagate leases across all GPFS nodes.
		</para></listitem>
		<listitem><para>
		<command>no</command> - 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.
		</para></listitem>
		</itemizedlist>
		</listitem>

		</varlistentry>

		<varlistentry>

		<term>gpfs:hsm = [ yes | no ]</term>
		<listitem>
		<para>
		Enable/Disable announcing if this FS has HSM enabled.
		</para>

		<itemizedlist>
		<listitem><para>
		<command>no(default)</command> - Do not announce HSM.
		</para></listitem>
		<listitem><para>
		<command>yes</command> - Announce HSM.
		</para></listitem>
		</itemizedlist>
		</listitem>

		</varlistentry>

		<varlistentry>

		<term>gpfs:getrealfilename = [ yes | no ]</term>
		<listitem>
		<para>
		Enable/Disable usage of the <command>gpfs_get_realfilename_path()</command> function.
		This improves the casesensitive wildcard file name access.
		</para>

		<itemizedlist>
		<listitem><para>
		<command>yes(default)</command> - use <command>gpfs_get_realfilename_path()</command>.
		</para></listitem>
		<listitem><para>
		<command>no</command> - do not use <command>gpfs_get_realfilename_path()</command>.
		It seems that <command>gpfs_get_realfilename_path()</command> doesn't work on AIX.
		</para></listitem>
		</itemizedlist>
		</listitem>

		</varlistentry>
		<varlistentry>

		<term>gpfs:winattr = [ yes | no ]</term>
		<listitem>
		<para>
		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.
		</para>

		<itemizedlist>
		<listitem><para>
		<command>no(default)</command> - do not use GPFS windows attributes.
		</para></listitem>
		<listitem><para>
		<command>yes</command> - use GPFS windows attributes.
		</para></listitem>
		</itemizedlist>
		</listitem>

		</varlistentry>
		<varlistentry>

		<term>gpfs:merge_writeappend = [ yes | no ]</term>
		<listitem>
		<para>
		GPFS ACLs doesn't know about the 'APPEND' right.
		This optionen lets Samba map the 'APPEND' right to 'WRITE'.
		</para>

		<itemizedlist>
		<listitem><para>
		<command>yes(default)</command> - map 'APPEND' to 'WRITE'.
		</para></listitem>
		<listitem><para>
		<command>no</command> - do not map 'APPEND' to 'WRITE'.
		</para></listitem>
		</itemizedlist>
		</listitem>

		</varlistentry>
		<varlistentry>

		<term>gpfs:refuse_dacl_protected = [ yes | no ]</term>
		<listitem>
		<para>
		As GPFS does not support the ACE4_FLAG_NO_PROPAGATE NFSv4 flag (which would be
		the mapping for the DESC_DACL_PROTECTED flag), the status of this flag is
		currently silently ignored by Samba. That means that if you deselect the "Allow
		inheritable permissions..." checkbox in Windows' ACL dialog and then apply the
		ACL, the flag will be back immediately.
		</para>
		<para>
		To make sure that automatic migration with e.g. robocopy does not lead to
		ACLs silently (and unintentionally) changed, you can set
		<command>gpfs:refuse_dacl_protected = yes</command> to enable an explicit
		check for this flag and if set, it will return NT_STATUS_NOT_SUPPORTED so
		errors are shown up on the Windows side and the Administrator is aware of
		the ACLs not being settable like intended
		</para>

		<itemizedlist>
		<listitem><para>
		<command>no(default)</command> - ignore the DESC_DACL_PROTECTED flags.
		</para></listitem>
		<listitem><para>
		<command>yes</command> - reject ACLs with DESC_DACL_PROTECTED.
		</para></listitem>
		</itemizedlist>
		</listitem>

		</varlistentry>
		<varlistentry>

		<term>gpfs:dfreequota = [ yes | no ]</term>
		<listitem>
		<para>
		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, the group
		quota of the primary group of the user and the fileset
		quota for the fileset containing the top level
		directory of the share.
		</para>

		<para>
		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.
		</para>

		<itemizedlist>
		<listitem><para>
		<command>yes</command> - include the quotas
		when reporting the share size and free space
		</para></listitem>
		<listitem><para>
		<command>no(default)</command> - do not include quotas,
		simply report the size and free space of the file system
		</para></listitem>
		</itemizedlist>
		</listitem>

		</varlistentry>
		<varlistentry>

		<term>gpfs:prealloc = [ yes | no ]</term>
		<listitem>
		<para>
		If set to yes the gpfs_prealloc function will be used in the
		fallocate callback when appropriate. If set to no gpfs_prealloc
		will not be used. In both cases the system and libc calls are
		avoided.
		</para>

		<itemizedlist>
		<listitem><para>
		<command>yes (default)</command> - Use gpfs_prealloc for the
		fallocate callback.
		</para></listitem>
		<listitem><para>
		<command>no</command> - Do not use gpfs_prealloc for the
		fallocate callback.
		</para></listitem>
		</itemizedlist>
		</listitem>

		</varlistentry>

		<varlistentry>

		<term>nfs4:mode = [ simple | special ]</term>
		<listitem>
		<para>
		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.
		</para>

		<para>The following MODEs are understood by the module:</para>
		<itemizedlist>
		<listitem><para><command>simple(default)</command> - do not use special IDs in GPFS ACEs</para></listitem>
		<listitem><para><command>special</command> - use special IDs in GPFS ACEs. </para> </listitem>
		</itemizedlist>
		</listitem>

		</varlistentry>


		<varlistentry>
		<term>nfs4:acedup = [dontcare|reject|ignore|merge]</term>
		<listitem>
		<para>
		This parameter configures how Samba handles duplicate ACEs encountered in GPFS ACLs.
		GPFS allows/creates duplicate ACE for different bits for same ID.
		</para>

		<para>Following is the behaviour of Samba for different values :</para>
		<itemizedlist>
		<listitem><para><command>dontcare (default)</command> - copy the ACEs as they come</para></listitem>
		<listitem><para><command>reject</command> - stop operation and exit with error on ACL set op</para></listitem>
		<listitem><para><command>ignore</command> - don't include the second matching ACE</para></listitem>
		<listitem><para><command>merge</command> - bitwise OR the 2 ace.flag fields and 2 ace.mask fields of the 2 duplicate ACEs into 1 ACE</para></listitem>
		</itemizedlist>
		</listitem>
		</varlistentry>


		<varlistentry>
		<term>nfs4:chown = [yes|no]</term>
		<listitem>
		<para>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.</para>
		<para>Some filesystems allow chown as a) giving b) stealing. It is the latter
		that is considered a risk.</para>

		<para>Following is the behaviour of Samba for different values : </para>
		<itemizedlist>
		<listitem><para><command>yes</command> - Enable chown if as supported by the under filesystem</para></listitem>
		<listitem><para><command>no (default)</command> - Disable chown</para></listitem>
		</itemizedlist>
		</listitem>
		</varlistentry>

		<varlistentry>
		<term>gpfs:syncio = [yes|no]</term>
		<listitem>
		<para>This parameter makes Samba open all files with O_SYNC.
		  This triggers optimizations in GPFS for workloads that
		  heavily share files.</para>

		<para>Following is the behaviour of Samba for different
		  values:
		</para>
		<itemizedlist>
		<listitem><para><command>yes</command> - Open files with O_SYNC
		</para></listitem>
		<listitem><para><command>no (default)</command> - Open files as
		    normal Samba would do
		</para></listitem>
		</itemizedlist>
		</listitem>
		</varlistentry>

	</variablelist>
</refsect1>

<refsect1>
	<title>EXAMPLES</title>

	<para>A GPFS mount can be exported via Samba as follows :</para>

<programlisting>
        <smbconfsection name="[samba_gpfs_share]"/>
	<smbconfoption name="vfs objects">gpfs</smbconfoption>
	<smbconfoption name="path">/test/gpfs_mount</smbconfoption>
	<smbconfoption name="nfs4: mode">special</smbconfoption>
	<smbconfoption name="nfs4: acedup">merge</smbconfoption>
</programlisting>
</refsect1>

<refsect1>
	<title>CAVEATS</title>
	<para>
	Depending on the version of gpfs, the <command>libgpfs_gpl</command>
	library or the <command>libgpfs</command> library is needed at
	runtime by the <command>gpfs</command> VFS module:
	Starting with gpfs 3.2.1 PTF8, the complete <command>libgpfs</command>
	is available as open source and <command>libgpfs_gpl</command> does no
	longer exist. With earlier versions of gpfs, only the
	<command>libgpfs_gpl</command> library was open source and could be
	used at run time.
	</para>
	<para>
	At build time, only the header file <command>gpfs_gpl.h</command>
	is required , which is a symlink to <command>gpfs.h</command> in
	gpfs versions newer than 3.2.1 PTF8.
	</para>
</refsect1>

<refsect1>
	<title>VERSION</title>
	<para>This man page is correct for version 3.0.25 of the Samba suite.
	</para>
</refsect1>

<refsect1>
	<title>AUTHOR</title>

	<para>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.</para>

	<para>The GPFS VFS module was created with contributions from
	Volker Lendecke and the developers at IBM.
	</para>

	<para> This manpage was created by the IBM FSCC team </para>
</refsect1>

</refentry>