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Diffstat (limited to 'docs-xml/Samba3-HOWTO')
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| -rw-r--r-- | docs-xml/Samba3-HOWTO/index.xml | 2 |
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diff --git a/docs-xml/Samba3-HOWTO/TOSHARG-Speed.xml b/docs-xml/Samba3-HOWTO/TOSHARG-Speed.xml deleted file mode 100644 index 18a15ae092..0000000000 --- a/docs-xml/Samba3-HOWTO/TOSHARG-Speed.xml +++ /dev/null @@ -1,327 +0,0 @@ -<?xml version="1.0" encoding="iso-8859-1"?> -<!DOCTYPE chapter PUBLIC "-//Samba-Team//DTD DocBook V4.2-Based Variant V1.0//EN" "http://www.samba.org/samba/DTD/samba-doc"> -<chapter id="speed"> - -<chapterinfo> - <author> - <firstname>Paul</firstname><surname>Cochrane</surname> - <affiliation> - <orgname>Dundee Limb Fitting Centre</orgname> - <address><email>paulc@dth.scot.nhs.uk</email></address> - </affiliation> - </author> - &author.jelmer; - &author.jht; -</chapterinfo> - -<title>Samba Performance Tuning</title> - -<sect1> -<title>Comparisons</title> - -<para> -The Samba server uses TCP to talk to the client, so if you are -trying to see if it performs well, you should really compare it to -programs that use the same protocol. The most readily available -programs for file transfer that use TCP are ftp or another TCP-based -SMB server. -</para> - -<para> -If you want to test against something like an NT or Windows for Workgroups server, then -you will have to disable all but TCP on either the client or -server. Otherwise, you may well be using a totally different protocol -(such as NetBEUI) and comparisons may not be valid. -</para> - -<para> -Generally, you should find that Samba performs similarly to ftp at raw -transfer speed. It should perform quite a bit faster than NFS, -although this depends on your system. -</para> - -<para> -Several people have done comparisons between Samba and Novell, NFS, or -Windows NT. In some cases Samba performed the best, in others the worst. I -suspect the biggest factor is not Samba versus some other system, but the -hardware and drivers used on the various systems. Given similar -hardware, Samba should certainly be competitive in speed with other -systems. -</para> - -</sect1> - -<sect1> -<title>Socket Options</title> - -<para> -There are a number of socket options that can greatly affect the -performance of a TCP-based server like Samba. -</para> - -<para> -The socket options that Samba uses are settable both on the command -line with the <option>-O</option> option and in the &smb.conf; file. -</para> - -<para> -The <smbconfoption name="socket options"/> section of the &smb.conf; manual page describes how -to set these and gives recommendations. -</para> - -<para> -Getting the socket options correct can make a big difference to your -performance, but getting them wrong can degrade it by just as -much. The correct settings are very dependent on your local network. -</para> - -<para> -The socket option TCP_NODELAY is the one that seems to make the biggest single difference -for most networks. Many people report that adding -<smbconfoption name="socket options">TCP_NODELAY</smbconfoption> -doubles the read performance of a Samba drive. The best explanation I have seen for -this is that the Microsoft TCP/IP stack is slow in sending TCP ACKs. -</para> - -<para> -There have been reports that setting <parameter>socket options = SO_RCVBUF=8192</parameter> in smb.conf -can seriously degrade Samba performance on the loopback adaptor (IP Address 127.0.0.1). It is strongly -recommended that before specifying any settings for <parameter>socket options</parameter>, the effect -first be quantitatively measured on the server being configured. -</para> - -</sect1> - -<sect1> -<title>Read Size</title> - -<para> -The option <smbconfoption name="read size"/> affects the overlap of disk -reads/writes with network reads/writes. If the amount of data being -transferred in several of the SMB commands (currently SMBwrite, SMBwriteX, and -SMBreadbraw) is larger than this value, then the server begins writing -the data before it has received the whole packet from the network, or -in the case of SMBreadbraw, it begins writing to the network before -all the data has been read from disk. -</para> - -<para> -This overlapping works best when the speeds of disk and network access -are similar, having little effect when the speed of one is much -greater than the other. -</para> - -<para> -The default value is 16384, but little experimentation has been -done as yet to determine the optimal value, and it is likely that the best -value will vary greatly between systems anyway. A value over 65536 is -pointless and will cause you to allocate memory unnecessarily. -</para> - -</sect1> - -<sect1> -<title>Max Xmit</title> - -<para> - At startup the client and server negotiate a <parameter>maximum transmit</parameter> size, -which limits the size of nearly all SMB commands. You can set the -maximum size that Samba will negotiate using the <smbconfoption name="max xmit"/> option -in &smb.conf;. Note that this is the maximum size of SMB requests that -Samba will accept, but not the maximum size that the client will accept. -The client maximum receive size is sent to Samba by the client, and Samba -honors this limit. -</para> - -<para> -It defaults to 65536 bytes (the maximum), but it is possible that some -clients may perform better with a smaller transmit unit. Trying values -of less than 2048 is likely to cause severe problems. -In most cases the default is the best option. -</para> - -</sect1> - -<sect1> -<title>Log Level</title> - -<para> -If you set the log level (also known as <smbconfoption name="debug level"/>) higher than 2, -then you may suffer a large drop in performance. This is because the -server flushes the log file after each operation, which can be quite -expensive. -</para> -</sect1> - -<sect1> -<title>Read Raw</title> - -<para> -The <smbconfoption name="read raw"/> operation is designed to be an optimized, low-latency -file read operation. A server may choose to not support it, -however, and Samba makes support for <smbconfoption name="read raw"/> optional, with it -being enabled by default. -</para> - -<para> -In some cases clients do not handle <smbconfoption name="read raw"/> very well and actually -get lower performance using it than they get using the conventional -read operations, so you might like to try <smbconfoption name="read raw">no</smbconfoption> and see what happens on your -network. It might lower, raise, or not affect your performance. Only -testing can really tell. -</para> - -</sect1> - -<sect1> -<title>Write Raw</title> - -<para> -The <smbconfoption name="write raw"/> operation is designed to be an optimized, low-latency -file write operation. A server may choose to not support it, however, and Samba makes support for -<smbconfoption name="write raw"/> optional, with it being enabled by default. -</para> - -<para> -Some machines may find <smbconfoption name="write raw"/> slower than normal write, in which -case you may wish to change this option. -</para> - -</sect1> - -<sect1> -<title>Slow Logins</title> - -<para> -Slow logins are almost always due to the password checking time. Using -the lowest practical <smbconfoption name="password level"/> will improve things. -</para> - -</sect1> - -<sect1> -<title>Client Tuning</title> - -<para> -Often a speed problem can be traced to the client. The client (for -example Windows for Workgroups) can often be tuned for better TCP -performance. Check the sections on the various clients in -<link linkend="Other-Clients">Samba and Other CIFS Clients</link>. -</para> - -</sect1> - -<sect1> -<title>Samba Performance Problem Due to Changing Linux Kernel</title> - -<para> -A user wrote the following to the mailing list: -</para> - -<blockquote> -<para> -<indexterm><primary>Gentoo</primary></indexterm> -<indexterm><primary>slow network</primary></indexterm> -I am running Gentoo on my server and Samba 2.2.8a. Recently I changed kernel versions from -<filename>linux-2.4.19-gentoo-r10</filename> to <filename>linux-2.4.20-wolk4.0s</filename>. Now I have a -performance issue with Samba. Many of you will probably say, <quote>Move to vanilla sources!</quote> Well, I -tried that and it didn't work. I have a 100MB LAN and two computers (Linux and Windows 2000). The Linux server -shares directories with DivX files, the client (Windows 2000) plays them via LAN. Before, when I was running -the 2.4.19 kernel, everything was fine, but now movies freeze and stop. I tried moving files between the -server and Windows, and it is terribly slow. -</para> -</blockquote> - -<para> -The answer he was given is: -</para> - -<blockquote> -<para> -<indexterm><primary>ifconfig</primary></indexterm> -<indexterm><primary>framing error</primary></indexterm> -<indexterm><primary>collisions</primary></indexterm> -Grab the mii-tool and check the duplex settings on the NIC. My guess is that it is a link layer issue, not an -application layer problem. Also run ifconfig and verify that the framing error, collisions, and so on, look -normal for ethernet. -</para> -</blockquote> - -</sect1> - -<sect1> -<title>Corrupt tdb Files</title> - -<para> -<indexterm><primary>PDC</primary></indexterm> -<indexterm><primary>mbd kept spawning</primary></indexterm> -<indexterm><primary>/var/locks/*.tdb</primary></indexterm> -Our Samba PDC server has been hosting three TB of data to our 500+ users [Windows NT/XP] for the last three -years using Samba without a problem. Today all shares went very slow. Also, the main smbd kept spawning new -processes, so we had 1600+ running SMDB's (normally we average 250). It crashed the SUN E3500 cluster twice. -After a lot of searching, I decided to <command>rm /var/locks/*.tdb</command>. Happy again. -</para> - -<para> -<emphasis>Question:</emphasis> Is there any method of keeping the *.tdb files in top condition, or -how can I detect early corruption? -</para> - -<para> -<indexterm><primary>tdbbackup</primary></indexterm> -<indexterm><primary>nmbd</primary></indexterm> -<emphasis>Answer:</emphasis> Yes, run <command>tdbbackup</command> each time after stopping nmbd and before starting nmbd. -</para> - -<para> -<emphasis>Question:</emphasis> What I also would like to mention is that the service latency seems -a lot lower than before the locks cleanup. Any ideas on keeping it top notch? -</para> - -<para> -<emphasis>Answer:</emphasis> Yes. Same answer as for previous question! -</para> - -</sect1> - -<sect1> -<title>Samba Performance is Very Slow</title> - -<para> -<indexterm><primary>slow performance</primary></indexterm> -A site reported experiencing very baffling symptoms with MYOB Premier opening and -accessing its data files. Some operations on the file would take between 40 and -45 seconds. -</para> - -<para> -<indexterm><primary>printer monitor</primary></indexterm> -<indexterm><primary>pauses</primary></indexterm> -It turned out that the printer monitor program running on the Windows -clients was causing the problems. From the logs, we saw activity coming -through with pauses of about 1 second. -</para> - -<para> -<indexterm><primary>networks access</primary></indexterm> -<indexterm><primary>printing now</primary></indexterm> -Stopping the monitor software resulted in the networks access at normal -(quick) speed. Restarting the program caused the speed to slow down -again. The printer was a Canon LBP-810 and the relevant task was -something like CAPON (not sure on spelling). The monitor software -displayed a "printing now" dialog on the client during printing. -</para> - -<para> -We discovered this by starting with a clean install of Windows and -trying the application at every step of the installation of other software -process (we had to do this many times). -</para> - -<para> -Moral of the story: Check everything (other software included)! -</para> - -</sect1> - -</chapter> diff --git a/docs-xml/Samba3-HOWTO/index.xml b/docs-xml/Samba3-HOWTO/index.xml index b2af47af6e..e496ce40b5 100644 --- a/docs-xml/Samba3-HOWTO/index.xml +++ b/docs-xml/Samba3-HOWTO/index.xml @@ -202,8 +202,6 @@ The chapters in this part each cover specific Samba features. <?latex \cleardoublepage ?> <xi:include href="TOSHARG-Compiling.xml"/> <?latex \cleardoublepage ?> - <xi:include href="TOSHARG-Speed.xml"/> - <?latex \cleardoublepage ?> <xi:include href="TOSHARG-SecureLDAP.xml"/> <?latex \cleardoublepage ?> <xi:include href="TOSHARG-Support.xml"/> |