diff options
Diffstat (limited to 'docs/docbook/projdoc/locking.xml')
| -rw-r--r-- | docs/docbook/projdoc/locking.xml | 137 |
1 files changed, 78 insertions, 59 deletions
diff --git a/docs/docbook/projdoc/locking.xml b/docs/docbook/projdoc/locking.xml index 0e508f682a..9a1ff9e8c8 100644 --- a/docs/docbook/projdoc/locking.xml +++ b/docs/docbook/projdoc/locking.xml @@ -62,7 +62,7 @@ that are specified when a file is open. </para> <para> -Record locking semantics under Unix are very different from record locking under +Record locking semantics under UNIX are very different from record locking under Windows. Versions of Samba before 2.2 have tried to use the native fcntl() unix system call to implement proper record locking between different Samba clients. This can not be fully correct due to several reasons. The simplest is the fact @@ -75,29 +75,29 @@ many more differences, too many to be listed here. <para> Samba 2.2 and above implements record locking completely independent of the underlying unix system. If a byte range lock that the client requests happens -to fall into the range 0-2^31, Samba hands this request down to the Unix system. +to fall into the range 0-2^31, Samba hands this request down to the UNIX system. All other locks can not be seen by unix anyway. </para> <para> -Strictly a SMB server should check for locks before every read and write call on -a file. Unfortunately with the way fcntl() works this can be slow and may overstress +Strictly an SMB server should check for locks before every read and write call on +a file. Unfortunately with the way fcntl() works this can be slow and may over-stress the <command>rpc.lockd</command>. It is also almost always unnecessary as clients are supposed to independently make locking calls before reads and writes anyway if locking is important to them. By default Samba only makes locking calls when explicitly asked -to by a client, but if you set <parameter>strict locking = yes</parameter> then it +to by a client, but if you set <smbconfoption><name>strict locking</name><value>yes</value></smbconfoption> then it will make lock checking calls on every read and write. </para> <para> -You can also disable byte range locking completely using <parameter>locking = no</parameter>. +You can also disable byte range locking completely using <smbconfoption><name>locking</name><value>no</value></smbconfoption>. This is useful for those shares that don't support locking or don't need it (such as cdroms). In this case Samba fakes the return codes of locking calls to tell clients that everything is OK. </para> <para> -The second class of locking is the <parameter>deny modes</parameter>. These +The second class of locking is the <emphasis>deny modes</emphasis>. These are set by an application when it opens a file to determine what types of access should be allowed simultaneously with its open. A client may ask for <constant>DENY_NONE</constant>, <constant>DENY_READ</constant>, @@ -328,19 +328,19 @@ in a performance bottleneck. </sect3> <sect3> -<title>Unix or NFS Client Accessed Files</title> +<title>UNIX or NFS Client Accessed Files</title> <para> -Local Unix and NFS clients access files without a mandatory +Local UNIX and NFS clients access files without a mandatory file locking mechanism. Thus, these client platforms are incapable of initiating an oplock break request from the server to a Windows client -that has a file cached. Local Unix or NFS file access can therefore +that has a file cached. Local UNIX or NFS file access can therefore write to a file that has been cached by a Windows client, which exposes the file to likely data corruption. </para> <para> -If files are shared between Windows clients, and either local Unix +If files are shared between Windows clients, and either local UNIX or NFS users, then turn opportunistic locking off. </para> @@ -409,7 +409,7 @@ the share. <title>Beware of Force User</title> <para> -Samba includes an &smb.conf; parameter called <parameter>force user</parameter> that changes +Samba includes an &smb.conf; parameter called <smbconfoption><name>force user</name></smbconfoption> that changes the user accessing a share from the incoming user to whatever user is defined by the smb.conf variable. If opportunistic locking is enabled on a share, the change in user access causes an oplock break to be sent @@ -426,7 +426,7 @@ Avoid the combination of the following: <itemizedlist> <listitem><para> - <parameter>force user</parameter> in the &smb.conf; share configuration. + <smbconfoption><name>force user</name></smbconfoption> in the &smb.conf; share configuration. </para></listitem> <listitem><para> @@ -449,8 +449,8 @@ administrator to adjust various properties of the oplock mechanism to account for timing and usage levels. These parameters provide good versatility for implementing oplocks in environments where they would likely cause problems. The parameters are: -<parameter>oplock break wait time</parameter>, -<parameter>oplock contention limit</parameter>. +<smbconfoption><name>oplock break wait time</name></smbconfoption>, +<smbconfoption><name>oplock contention limit</name></smbconfoption>. </para> <para> @@ -514,7 +514,7 @@ enabled and disabled. <para> Opportunistic Locking is a unique Windows file locking feature. It is not really file locking, but is included in most discussions of Windows -file locking, so is considered a defacto locking feature. +file locking, so is considered a de facto locking feature. Opportunistic Locking is actually part of the Windows client file caching mechanism. It is not a particularly robust or reliable feature when implemented on the variety of customized networks that exist in @@ -557,7 +557,7 @@ oplock aware at this time. <para> Unless your system supports kernel oplocks, you should disable oplocks if you are -accessing the same files from both Unix/Linux and SMB clients. Regardless, oplocks should +accessing the same files from both UNIX/Linux and SMB clients. Regardless, oplocks should always be disabled if you are sharing a database file (e.g., Microsoft Access) between multiple clients, as any break the first client receives will affect synchronisation of the entire file (not just the single record), which will result in a noticeable performance @@ -594,11 +594,11 @@ You can disable oplocks on a per-share basis with the following: </para> <para> -<programlisting> -[acctdata] - oplocks = False - level2 oplocks = False -</programlisting> +<smbconfblock> +<smbconfsection>[acctdata]</smbconfsection> +<smbconfoption><name>oplocks</name><value>False</value></smbconfoption> +<smbconfoption><name>level2 oplocks</name><value>False</value></smbconfoption> +</smbconfblock> </para> <para> @@ -611,9 +611,9 @@ Alternately, you could disable oplocks on a per-file basis within the share: </para> <para> -<programlisting> - veto oplock files = /*.mdb/*.MDB/*.dbf/*.DBF/ -</programlisting> + <smbconfblock> +<smbconfoption><name>veto oplock files</name><value>/*.mdb/*.MDB/*.dbf/*.DBF/</value></smbconfoption> +</smbconfblock> </para> <para> @@ -641,10 +641,9 @@ basis in the &smb.conf; file. </para> <para> -<programlisting> -[global] -kernel oplocks = yes -</programlisting> + <smbconfblock> +<smbconfoption><name>kernel oplocks</name><value>yes</value></smbconfoption> +</smbconfblock> The default is "no". </para> @@ -663,17 +662,18 @@ enabled on a per-share basis, or globally for the entire server, in the </para> <para> -<programlisting><title>Example Veto OpLock Settings</title> -[global] - veto oplock files = /filename.htm/*.txt/ +<smbconfexample> + <title>Share with some files oplocked</title> +<smbconfsection>[global]</smbconfsection> +<smbconfoption><name>veto oplock files</name><value>/filename.htm/*.txt/</value></smbconfoption> -[share_name] - veto oplock files = /*.exe/filename.ext/ -</programlisting> +<smbconfsection>[share_name]</smbconfsection> +<smbconfoption><name>veto oplock files</name><value>/*.exe/filename.ext/</value></smbconfoption> +</smbconfexample> </para> <para> -<emphasis>Oplock break wait time</emphasis> is an &smb.conf; parameter that adjusts the time + <smbconfoption><name>oplock break wait time</name></smbconfoption> is an &smb.conf; parameter that adjusts the time interval for Samba to reply to an oplock break request. Samba recommends "DO NOT CHANGE THIS PARAMETER UNLESS YOU HAVE READ AND UNDERSTOOD THE SAMBA OPLOCK CODE." Oplock Break Wait Time can only be @@ -681,10 +681,9 @@ configured globally in the &smb.conf; file: </para> <para> -<programlisting> -[global] - oplock break wait time = 0 (default) -</programlisting> + <smbconfblock> +<smbconfoption><name>oplock break wait time</name><value> 0 (default)</value></smbconfoption> +</smbconfblock> </para> <para> @@ -698,13 +697,13 @@ the entire server, in the &smb.conf; file: </para> <para> -<programlisting> -[global] - oplock break contention limit = 2 (default) + <smbconfexample> +<smbconfsection>[global]</smbconfsection> +<smbconfoption><name>oplock break contention limit</name><value> 2 (default)</value></smbconfoption> -[share_name] - oplock break contention limit = 2 (default) -</programlisting> +<smbconfsection>[share_name]</smbconfsection> +<smbconfoption><name>oplock break contention limit</name><value> 2 (default)</value></smbconfoption> +</smbconfexample> </para> </sect3> @@ -919,7 +918,7 @@ potentially cause loss of cached data. <title>Persistent Data Corruption</title> <para> -If you have applied all of the settings discussed in this paper but data corruption problems +If you have applied all of the settings discussed in this chapter but data corruption problems and other symptoms persist, here are some additional things to check out: </para> @@ -984,14 +983,15 @@ so far: <title>locking.tdb error messages</title> <para> - <screen> - > We are seeing lots of errors in the samba logs like: - > - > tdb(/usr/local/samba_2.2.7/var/locks/locking.tdb): rec_read bad magic - > 0x4d6f4b61 at offset=36116 - > - > What do these mean? - </screen> + <quote> + We are seeing lots of errors in the samba logs like: +<programlisting> +tdb(/usr/local/samba_2.2.7/var/locks/locking.tdb): rec_read bad magic + 0x4d6f4b61 at offset=36116 +</programlisting> + + What do these mean? + </quote> </para> <para> @@ -1000,6 +1000,25 @@ so far: </sect2> + <sect2> + <title>Problems saving files in MS Office on Windows XP</title> + + <para>This is a bug in Windows XP. More information can be + found in <ulink url="http://support.microsoft.com/?id=812937">Microsoft Knowledge Base article 812937</ulink>.</para> + + </sect2> + + <sect2> + + <title>Long delays deleting files over network with XP SP1</title> + + <para><quote>It sometimes takes approximately 35 seconds to delete files over the network after XP SP1 has been applied</quote></para> + + <para>This is a bug in Windows XP. More information can be + found in <ulink url="http://support.microsoft.com/?id=811492"> + Microsoft Knowledge Base article 811492</ulink>.</para> + </sect2> + </sect1> <sect1> @@ -1019,22 +1038,22 @@ Section of the Microsoft MSDN Library on opportunistic locking: Opportunistic Locks, Microsoft Developer Network (MSDN), Windows Development > Windows Base Services > Files and I/O > SDK Documentation > File Storage > File Systems > About File Systems > Opportunistic Locks, Microsoft Corporation. -<ulink url="http://msdn.microsoft.com/library/en-us/fileio/storage_5yk3.asp">http://msdn.microsoft.com/library/en-us/fileio/storage_5yk3.asp</ulink> +<ulink noescape="1" url="http://msdn.microsoft.com/library/en-us/fileio/storage_5yk3.asp">http://msdn.microsoft.com/library/en-us/fileio/storage_5yk3.asp</ulink> </para> <para> Microsoft Knowledge Base Article Q224992 "Maintaining Transactional Integrity with OPLOCKS", -Microsoft Corporation, April 1999, <ulink url="http://support.microsoft.com/default.aspx?scid=kb;en-us;Q224992">http://support.microsoft.com/default.aspx?scid=kb;en-us;Q224992</ulink>. +Microsoft Corporation, April 1999, <ulink noescape="1" url="http://support.microsoft.com/default.aspx?scid=kb;en-us;Q224992">http://support.microsoft.com/default.aspx?scid=kb;en-us;Q224992</ulink>. </para> <para> Microsoft Knowledge Base Article Q296264 "Configuring Opportunistic Locking in Windows 2000", -Microsoft Corporation, April 2001, <ulink url="http://support.microsoft.com/default.aspx?scid=kb;en-us;Q296264">http://support.microsoft.com/default.aspx?scid=kb;en-us;Q296264</ulink>. +Microsoft Corporation, April 2001, <ulink noescape="1" url="http://support.microsoft.com/default.aspx?scid=kb;en-us;Q296264">http://support.microsoft.com/default.aspx?scid=kb;en-us;Q296264</ulink>. </para> <para> Microsoft Knowledge Base Article Q129202 "PC Ext: Explanation of Opportunistic Locking on Windows NT", - Microsoft Corporation, April 1995, <ulink url="http://support.microsoft.com/default.aspx?scid=kb;en-us;Q129202">http://support.microsoft.com/default.aspx?scid=kb;en-us;Q129202</ulink>. + Microsoft Corporation, April 1995, <ulink noescape="1" url="http://support.microsoft.com/default.aspx?scid=kb;en-us;Q129202">http://support.microsoft.com/default.aspx?scid=kb;en-us;Q129202</ulink>. </para> </sect1> |