svn commit: samba-docs r597 - in trunk/Samba-Guide: .

jht at samba.org jht at samba.org
Sat May 28 04:59:58 GMT 2005


Author: jht
Date: 2005-05-28 04:59:58 +0000 (Sat, 28 May 2005)
New Revision: 597

WebSVN: http://websvn.samba.org/cgi-bin/viewcvs.cgi?view=rev&root=samba-docs&rev=597

Log:
More edits.
Modified:
   trunk/Samba-Guide/SBE-HighAvailability.xml
   trunk/Samba-Guide/SBE-UpgradingSamba.xml


Changeset:
Modified: trunk/Samba-Guide/SBE-HighAvailability.xml
===================================================================
--- trunk/Samba-Guide/SBE-HighAvailability.xml	2005-05-28 00:43:19 UTC (rev 596)
+++ trunk/Samba-Guide/SBE-HighAvailability.xml	2005-05-28 04:59:58 UTC (rev 597)
@@ -613,31 +613,89 @@
 	</sect2>
 
 	<sect2>
-		<title>Key Points Learned</title>
+	<title>Large Directories</title>
 
-		<para>
-		This chapter has touched in broad sweeps on a number of simple steps that can be taken
-		to ensure that your Samba network is resilient, scalable, and reliable, and that it
-		performs well.
-		</para>
+	<para>
+	There exist applications that create or manage directories containing many thousands of files. Such
+	applications typically generate many small files (less than 100 KB). At the best of times under UNIX
+	listing of the files in a directory that contains many files is slow. By default Windows NT, 200x, 
+	and XP Pro cause network file system directory lookups on a Samba server to be performed for both 
+	the case preserving file name as well as for the mangled (8.3) file name. This incurs a huge overhead
+	on the Samba server that may slow down the system dramatically.
+	</para>
 
-		<para>
-		Always keep in mind that someone is responsible to maintain and manage your design.
-		In the long term, that may not be you. Spare a thought for your successor and give him or
-		her an even break.
-		</para>
+	<para>
+	In an extreme case the performance impact was dramatic. File transfer from the Samba server to a Windows
+	XP Professional workstation over 1 Gigabit Ethernet for 250-500 KB files was measured at approximately
+	30 MB/sec. But when tranfering a directory containng 120,000 files, all from 50KB to 60KB in size, the
+	transfer rate to the same workstation was measured at approximately 1.5 KB/sec. The net transfer was
+	of the order of a factor of 20-fold slower.
+	</para>
 
-		<para>
-		<indexterm><primary>assumptions</primary></indexterm>
-		Last, but not least, you should not only keep the network design simple, but also be sure it is
-		well documented. This book may serve as your pattern for documenting every
-		aspect of your design, its implementation, and particularly the objects and assumptions
-		that underlie it.
-		</para>
+	<para>
+	The symptoms that will be observed on the Samba server when a large directory is accessed will be that
+	aggregate I/O (typically blocks read) will be relatively low, yet the wait I/O times will be incredably
+	long while at the same time the read queue is large. Close observation will show that the hard drive
+	that the file system is on will be thrashing wildly.
+	</para>
 
+	<para>
+	Samba-3.0.12, and later, includes new code that radically improves Samba perfomance. The secret to this is
+	really in the <smbconfoption name="case sensitive">True</smbconfoption> line. This tells smbd never to scan
+	for case-insensitive versions of names. So if an application asks for a file called <filename>FOO</filename>,
+	and it can not be found by a simple stat call, then smbd will return file not found immediately without
+	scanning the containing directory for a version of a different case.
+	</para>
+
+	<para>
+	Canonicalize all the files in the directory to have one case, upper or lower - either will do. Then set up 
+	a new custom share for the application as follows:
+	<screen>
+	[bigshare]
+			path = /data/xrayfiles/neurosurgeons/
+			read only = no
+			case sensitive = True
+			default case = upper
+			preserve case = no
+			short preserve case = no
+	</screen>
+	</para>
+
+	<para>
+	All files and directories under the <parameter>path</parameter> directory must be in the same case
+	as specified in the &smb.conf; stanza. This means that smbd will not be able to find lower case 
+	filenames with these settings.  Note, this is done on a per-share basis.
+	</para>
+
 	</sect2>
 
 </sect1>
 
+<sect1>
+	<title>Key Points Learned</title>
+
+	<para>
+	This chapter has touched in broad sweeps on a number of simple steps that can be taken
+	to ensure that your Samba network is resilient, scalable, and reliable, and that it
+	performs well.
+	</para>
+
+	<para>
+	Always keep in mind that someone is responsible to maintain and manage your design.
+	In the long term, that may not be you. Spare a thought for your successor and give him or
+	her an even break.
+	</para>
+
+	<para>
+	<indexterm><primary>assumptions</primary></indexterm>
+	Last, but not least, you should not only keep the network design simple, but also be sure it is
+	well documented. This book may serve as your pattern for documenting every
+	aspect of your design, its implementation, and particularly the objects and assumptions
+	that underlie it.
+	</para>
+
+</sect1>
+
+
 </chapter>
 

Modified: trunk/Samba-Guide/SBE-UpgradingSamba.xml
===================================================================
--- trunk/Samba-Guide/SBE-UpgradingSamba.xml	2005-05-28 00:43:19 UTC (rev 596)
+++ trunk/Samba-Guide/SBE-UpgradingSamba.xml	2005-05-28 04:59:58 UTC (rev 597)
@@ -509,6 +509,27 @@
 
 	</sect3>
 
+	<sect3>
+	<title>Updates and Changes in Idealx smbldap-tools</title>
+
+	<para>
+	The smbldap-tools have been maturing rapidly over the past year. With maturation comes change.
+	The location of the <filename>smbldap.conf</filename> and the <filename>smbldap_bind.conf</filename>
+	configuration files have been moved from the directory <filename>/etc/smbldap-tools</filenam> to
+	the new location of <filename>/etc/opt/IDEALX/smblda-tools</filename> directory.
+	</para>
+
+	<para>
+	The smbldap-tools maintains an entry in the LDAP directory in which it stores the next
+	values that should be used for UID and GID allocation for POSIX accounts that are created
+	using this tool. The DIT location of these values has changed recently. The original
+	<constant>sambaUnixIdPooldn object</constant> entity was stored in a directory entry (DIT object)
+	called <constant>NextFreeUnixId</constant>, this has been changed to the DIT object
+	<constant>sambaDomainName</constant>. Anyone who updates from an older version to the
+	current release should note that the information stored under <constant>NextFreeUnixId</constant>
+	must now be relocated to the DIT object <constant>sambaDomainName</constant>.
+	</para>
+
 	</sect2>
 
 </sect1>



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