<chapter id="diagnosis"> <chapterinfo> &author.tridge; &author.jelmer; <pubdate>Wed Jan 15</pubdate> </chapterinfo> <title>The Samba checklist</title> <sect1> <title>Introduction</title> <para> This file contains a list of tests you can perform to validate your Samba server. It also tells you what the likely cause of the problem is if it fails any one of these steps. If it passes all these tests then it is probably working fine. </para> <para> You should do ALL the tests, in the order shown. We have tried to carefully choose them so later tests only use capabilities verified in the earlier tests. However, do not stop at the first error as there have been some instances when continuing with the tests has helped to solve a problem. </para> <para> If you send one of the samba mailing lists an email saying "it doesn't work" and you have not followed this test procedure then you should not be surprised if your email is ignored. </para> </sect1> <sect1> <title>Assumptions</title> <para> In all of the tests it is assumed you have a Samba server called BIGSERVER and a PC called ACLIENT both in workgroup TESTGROUP. </para> <para> The procedure is similar for other types of clients. </para> <para> It is also assumed you know the name of an available share in your &smb.conf;. I will assume this share is called <replaceable>tmp</replaceable>. You can add a <replaceable>tmp</replaceable> share like this by adding the following to &smb.conf;: </para> <para><smbconfexample> <title>smb.conf with [tmp] share</title> <smbconfsection>[tmp]</smbconfsection> <smbconfoption><name>comment</name><value>temporary files </value></smbconfoption> <smbconfoption><name>path</name><value>/tmp</value></smbconfoption> <smbconfoption><name>read only</name><value>yes</value></smbconfoption> </smbconfexample> </para> <note><para> These tests assume version 3.0 or later of the samba suite. Some commands shown did not exist in earlier versions. </para></note> <para> Please pay attention to the error messages you receive. If any error message reports that your server is being unfriendly you should first check that your IP name resolution is correctly set up. eg: Make sure your <filename>/etc/resolv.conf</filename> file points to name servers that really do exist. </para> <para> Also, if you do not have DNS server access for name resolution please check that the settings for your &smb.conf; file results in <command>dns proxy = no</command>. The best way to check this is with <userinput>testparm smb.conf</userinput>. </para> <indexterm><primary>log files</primary><secondary>monitoring</secondary></indexterm> <para> It is helpful to monitor the log files during testing by using the <command>tail -F <replaceable>log_file_name</replaceable></command> in a separate terminal console (use ctrl-alt-F1 through F6 or multiple terminals in X). Relevant log files can be found (for default installations) in <filename>/usr/local/samba/var</filename>. Also, connection logs from machines can be found here or possibly in <filename>/var/log/samba</filename> depending on how or if you specified logging in your &smb.conf; file. </para> <para> If you make changes to your &smb.conf; file while going through these test, don't forget to restart &smbd; and &nmbd;. </para> </sect1> <sect1> <title>The tests</title> <procedure> <title>Diagnosing your samba server</title> <indexterm><primary>testparm</primary></indexterm> <step performance="required"> <para> In the directory in which you store your &smb.conf; file, run the command <userinput>testparm smb.conf</userinput>. If it reports any errors then your &smb.conf; configuration file is faulty. </para> <note><para> Your &smb.conf; file may be located in: <filename>/etc/samba</filename> Or in: <filename>/usr/local/samba/lib</filename> </para></note> </step> <step performance="required"> <para> Run the command <userinput>ping BIGSERVER</userinput> from the PC and <userinput>ping ACLIENT</userinput> from the unix box. If you don't get a valid response then your TCP/IP software is not correctly installed. </para> <para> Note that you will need to start a "dos prompt" window on the PC to run ping. </para> <para> If you get a message saying <errorname>host not found</errorname> or similar then your DNS software or <filename>/etc/hosts</filename> file is not correctly setup. It is possible to run samba without DNS entries for the server and client, but I assume you do have correct entries for the remainder of these tests. </para> <para> Another reason why ping might fail is if your host is running firewall software. You will need to relax the rules to let in the workstation in question, perhaps by allowing access from another subnet (on Linux this is done via the <application>ipfwadm</application> program.) </para> <note> <para> Modern Linux distributions install ipchains/iptables by default. This is a common problem that is often overlooked. </para> </note> </step> <step performance="required"> <para> Run the command <userinput>smbclient -L BIGSERVER</userinput> on the unix box. You should get a list of available shares back. </para> <para> If you get a error message containing the string "Bad password" then you probably have either an incorrect <command>hosts allow</command>, <command>hosts deny</command> or <command>valid users</command> line in your &smb.conf;, or your guest account is not valid. Check what your guest account is using &testparm; and temporarily remove any <command>hosts allow</command>, <command>hosts deny</command>, <command>valid users</command> or <command>invalid users</command> lines. </para> <para> If you get a <errorname>connection refused</errorname> response then the smbd server may not be running. If you installed it in inetd.conf then you probably edited that file incorrectly. If you installed it as a daemon then check that it is running, and check that the netbios-ssn port is in a LISTEN state using <userinput>netstat -a</userinput>. </para> <note><para> <indexterm><primary>inetd</primary></indexterm> <indexterm><primary>xinetd</primary><see>inetd</see></indexterm> Some Unix / Linux systems use <command>xinetd</command> in place of <command>inetd</command>. Check your system documentation for the location of the control file/s for your particular system implementation of this network super daemon. </para></note> <para> If you get a <errorname>session request failed</errorname> then the server refused the connection. If it says "Your server software is being unfriendly" then its probably because you have invalid command line parameters to &smbd;, or a similar fatal problem with the initial startup of &smbd;. Also check your config file (&smb.conf;) for syntax errors with &testparm; and that the various directories where samba keeps its log and lock files exist. </para> <para> There are a number of reasons for which smbd may refuse or decline a session request. The most common of these involve one or more of the following &smb.conf; file entries: </para> <para><smbconfblock> <smbconfoption><name>hosts deny</name><value>ALL</value></smbconfoption> <smbconfoption><name>hosts allow</name><value>xxx.xxx.xxx.xxx/yy</value></smbconfoption> <smbconfoption><name>bind interfaces only</name><value>Yes</value></smbconfoption> </smbconfblock></para> <para> In the above, no allowance has been made for any session requests that will automatically translate to the loopback adapter address 127.0.0.1. To solve this problem change these lines to: </para> <para><smbconfblock> <smbconfoption><name>hosts deny</name><value>ALL</value></smbconfoption> <smbconfoption><name>hosts allow</name><value>xxx.xxx.xxx.xxx/yy 127.</value></smbconfoption> </smbconfblock></para> <para> Do <emphasis>not</emphasis> use the <smbconfoption><name>bind interfaces only</name></smbconfoption> parameter where you may wish to use the samba password change facility, or where &smbclient; may need to access a local service for name resolution or for local resource connections. (Note: the <smbconfoption><name>bind interfaces only</name></smbconfoption> parameter deficiency where it will not allow connections to the loopback address will be fixed soon). </para> <para> <indexterm><primary>inetd</primary></indexterm> Another common cause of these two errors is having something already running on port <constant>139</constant>, such as Samba (ie: &smbd; is running from <application>inetd</application> already) or something like Digital's Pathworks. Check your <filename>inetd.conf</filename> file before trying to start &smbd; as a daemon, it can avoid a lot of frustration! </para> <para> And yet another possible cause for failure of this test is when the subnet mask and / or broadcast address settings are incorrect. Please check that the network interface IP Address / Broadcast Address / Subnet Mask settings are correct and that Samba has correctly noted these in the <filename>log.nmbd</filename> file. </para> </step> <step performance="required"> <para> Run the command <userinput>nmblookup -B BIGSERVER __SAMBA__</userinput>. You should get the IP address of your Samba server back. </para> <para> If you don't then nmbd is incorrectly installed. Check your <filename>inetd.conf</filename> if you run it from there, or that the daemon is running and listening to udp port 137. </para> <para> One common problem is that many inetd implementations can't take many parameters on the command line. If this is the case then create a one-line script that contains the right parameters and run that from inetd. </para> </step> <step performance="required"> <para>run the command <userinput>nmblookup -B ACLIENT '*'</userinput></para> <para> You should get the PCs IP address back. If you don't then the client software on the PC isn't installed correctly, or isn't started, or you got the name of the PC wrong. </para> <para> If ACLIENT doesn't resolve via DNS then use the IP address of the client in the above test. </para> </step> <step performance="required"> <para> Run the command <userinput>nmblookup -d 2 '*'</userinput> </para> <para> This time we are trying the same as the previous test but are trying it via a broadcast to the default broadcast address. A number of NetBIOS / TCP/IP hosts on the network should respond, although Samba may not catch all of the responses in the short time it listens. You should see <errorname>got a positive name query response</errorname> messages from several hosts. </para> <para> If this doesn't give a similar result to the previous test then nmblookup isn't correctly getting your broadcast address through its automatic mechanism. In this case you should experiment with the <smbconfoption><name>interfaces</name></smbconfoption> option in &smb.conf; to manually configure your IP address, broadcast and netmask. </para> <para> If your PC and server aren't on the same subnet then you will need to use the <option>-B</option> option to set the broadcast address to that of the PCs subnet. </para> <para> This test will probably fail if your subnet mask and broadcast address are not correct. (Refer to TEST 3 notes above). </para> </step> <step performance="required"> <indexterm><primary>smbclient</primary></indexterm> <para> Run the command <userinput>smbclient //BIGSERVER/TMP</userinput>. You should then be prompted for a password. You should use the password of the account you are logged into the unix box with. If you want to test with another account then add the <option>-U <replaceable>accountname</replaceable></option> option to the end of the command line. eg: <userinput>smbclient //bigserver/tmp -Ujohndoe</userinput> </para> <note><para> It is possible to specify the password along with the username as follows: <userinput>smbclient //bigserver/tmp -Ujohndoe%secret</userinput> </para></note> <para> Once you enter the password you should get the <prompt>smb></prompt> prompt. If you don't then look at the error message. If it says <errorname>invalid network name</errorname> then the service <emphasis>"tmp"</emphasis> is not correctly setup in your &smb.conf;. </para> <para> If it says <errorname>bad password</errorname> then the likely causes are: </para> <orderedlist> <listitem> <para> you have shadow passwords (or some other password system) but didn't compile in support for them in &smbd; </para> </listitem> <listitem> <para> your <smbconfoption><name>valid users</name></smbconfoption> configuration is incorrect </para> </listitem> <listitem> <para> you have a mixed case password and you haven't enabled the <smbconfoption><name>password level</name></smbconfoption> option at a high enough level </para> </listitem> <listitem> <para> the <smbconfoption><name>path</name></smbconfoption> line in &smb.conf; is incorrect. Check it with &testparm; </para> </listitem> <listitem> <para> you enabled password encryption but didn't map unix to samba users. Run <screen><userinput>smbpasswd -a <replaceable>username</replaceable></userinput></screen>. </para> </listitem> </orderedlist> <para> Once connected you should be able to use the commands <command>dir</command> <command>get</command> <command>put</command> etc. Type <command>help <replaceable>command</replaceable></command> for instructions. You should especially check that the amount of free disk space shown is correct when you type <command>dir</command>. </para> </step> <step performance="required"> <para> On the PC, type the command <userinput>net view \\BIGSERVER</userinput>. You will need to do this from within a "dos prompt" window. You should get back a list of available shares on the server. </para> <para> If you get a <errorname>network name not found</errorname> or similar error then netbios name resolution is not working. This is usually caused by a problem in nmbd. To overcome it you could do one of the following (you only need to choose one of them): </para> <orderedlist> <listitem><para> fixup the &nmbd; installation </para></listitem> <listitem><para> add the IP address of BIGSERVER to the <command>wins server</command> box in the advanced TCP/IP setup on the PC. </para></listitem> <listitem><para> enable windows name resolution via DNS in the advanced section of the TCP/IP setup </para></listitem> <listitem><para> add BIGSERVER to your lmhosts file on the PC. </para></listitem> </orderedlist> <para> If you get a <errorname>invalid network name</errorname> or <errorname>bad password error</errorname> then the same fixes apply as they did for the <userinput>smbclient -L</userinput> test above. In particular, make sure your <command>hosts allow</command> line is correct (see the man pages) </para> <para> Also, do not overlook that fact that when the workstation requests the connection to the samba server it will attempt to connect using the name with which you logged onto your Windows machine. You need to make sure that an account exists on your Samba server with that exact same name and password. </para> <para> If you get <errorname>specified computer is not receiving requests</errorname> or similar it probably means that the host is not contactable via tcp services. Check to see if the host is running tcp wrappers, and if so add an entry in the <filename>hosts.allow</filename> file for your client (or subnet, etc.) </para> </step> <step performance="required"> <para> Run the command <userinput>net use x: \\BIGSERVER\TMP</userinput>. You should be prompted for a password then you should get a <computeroutput>command completed successfully</computeroutput> message. If not then your PC software is incorrectly installed or your smb.conf is incorrect. make sure your <command>hosts allow</command> and other config lines in &smb.conf; are correct. </para> <para> It's also possible that the server can't work out what user name to connect you as. To see if this is the problem add the line <smbconfoption><name>user</name><value>username</value></smbconfoption> to the <smbconfsection>[tmp]</smbconfsection> section of &smb.conf; where <replaceable>username</replaceable> is the username corresponding to the password you typed. If you find this fixes things you may need the username mapping option. </para> <para> It might also be the case that your client only sends encrypted passwords and you have <smbconfoption><name>encrypt passwords</name><value>no</value></smbconfoption> in &smb.conf; Turn it back on to fix. </para> </step> <step performance="required"> <para> Run the command <userinput>nmblookup -M <replaceable>testgroup</replaceable></userinput> where <replaceable>testgroup</replaceable> is the name of the workgroup that your Samba server and Windows PCs belong to. You should get back the IP address of the master browser for that workgroup. </para> <para> If you don't then the election process has failed. Wait a minute to see if it is just being slow then try again. If it still fails after that then look at the browsing options you have set in &smb.conf;. Make sure you have <smbconfoption><name>preferred master</name><value>yes</value></smbconfoption> to ensure that an election is held at startup. </para> </step> <step performance="required"> <para> From file manager try to browse the server. Your samba server should appear in the browse list of your local workgroup (or the one you specified in &smb.conf;). You should be able to double click on the name of the server and get a list of shares. If you get a "invalid password" error when you do then you are probably running WinNT and it is refusing to browse a server that has no encrypted password capability and is in user level security mode. In this case either set <smbconfoption><name>security</name><value>server</value></smbconfoption> AND <smbconfoption><name>password server</name><value>Windows_NT_Machine</value></smbconfoption> in your &smb.conf; file, or make sure <smbconfoption><name>encrypt passwords</name></smbconfoption> is set to "yes". </para> </step> </procedure> </sect1> </chapter>