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  • only in /asuswrt-rt-n18u-9.0.0.4.380.2695/release/src-rt-6.x.4708/router/samba-3.5.8/docs-xml/Samba3-HOWTO/
1<?xml version="1.0" encoding="iso-8859-1"?>
2<!DOCTYPE chapter PUBLIC "-//Samba-Team//DTD DocBook V4.2-Based Variant V1.0//EN" "http://www.samba.org/samba/DTD/samba-doc">
3<chapter id="Portability">
4<chapterinfo>
5	&author.jelmer;
6	&author.jht;
7	<!-- Some other people as well, but there were no author names in the text files this file is based on-->
8</chapterinfo>
9
10<title>Portability</title>
11
12<para>
13<indexterm><primary>platforms</primary></indexterm>
14<indexterm><primary>compatible</primary></indexterm>
15Samba works on a wide range of platforms, but the interface all the 
16platforms provide is not always compatible. This chapter contains 
17platform-specific information about compiling and using Samba.</para>
18
19<sect1>
20<title>HPUX</title>
21
22<para>
23<indexterm><primary>/etc/logingroup</primary></indexterm>
24<indexterm><primary>/etc/group</primary></indexterm>
25Hewlett-Packard's implementation of supplementary groups is nonstandard (for
26historical reasons). There are two group files, <filename>/etc/group</filename> and
27<filename>/etc/logingroup</filename>; the system maps UIDs to numbers using the former, but
28initgroups() reads the latter. Most system admins who know the ropes
29symlink <filename>/etc/group</filename> to <filename>/etc/logingroup</filename>
30(hard-link does not work for reasons too obtuse to go into here). initgroups() will complain if one of the
31groups you're in, in <filename>/etc/logingroup</filename>, has what it considers to be an invalid
32ID, which means outside the range <constant>[0..UID_MAX]</constant>, where <constant>UID_MAX</constant> is
3360000 currently on HP-UX. This precludes -2 and 65534, the usual <constant>nobody</constant>
34GIDs.
35</para>
36
37<para>
38If you encounter this problem, make sure the programs that are failing 
39to initgroups() are run as users, not in any groups with GIDs outside the 
40allowed range.
41</para>
42
43<para>
44This is documented in the HP manual pages under setgroups(2) and passwd(4).
45</para>
46
47<para>
48<indexterm><primary>gcc</primary></indexterm>
49<indexterm><primary>ANSI compiler</primary></indexterm>
50On HP-UX you must use gcc or the HP ANSI compiler. The free compiler
51that comes with HP-UX is not ANSI compliant and cannot compile Samba.
52</para>
53
54</sect1>
55
56<sect1>
57<title>SCO UNIX</title>
58
59<para> 
60If you run an old version of SCO UNIX, you may need to get important 
61TCP/IP patches for Samba to work correctly. Without the patch, you may 
62encounter corrupt data transfers using Samba.
63</para>
64
65<para>
66The patch you need is UOD385 Connection Drivers SLS. It is available from
67SCO <ulink noescape="1" url="ftp://ftp.sco.com/">ftp.sco.com</ulink>, directory SLS,
68files uod385a.Z and uod385a.ltr.Z).
69</para>
70
71<para>
72The information provided here refers to an old version of SCO UNIX. If you require
73binaries for more recent SCO UNIX products, please contact SCO to obtain packages that are
74ready to install. You should also verify with SCO that your platform is up to date for the
75binary packages you will install. This is important if you wish to avoid data corruption
76problems with your installation. To build Samba for SCO UNIX products  may
77require significant patching of Samba source code. It is much easier to obtain binary
78packages directly from SCO.
79</para>
80
81</sect1>
82
83<sect1>
84<title>DNIX</title>
85
86<para>
87DNIX has a problem with seteuid() and setegid(). These routines are
88needed for Samba to work correctly, but they were left out of the DNIX
89C library for some reason.
90</para>
91
92<para>
93For this reason Samba by default defines the macro NO_EID in the DNIX
94section of includes.h. This works around the problem in a limited way,
95but it is far from ideal, and some things still will not work right.
96</para>
97
98<para> 
99To fix the problem properly, you need to assemble the following two
100functions and then either add them to your C library or link them into
101Samba. Put the following in the file <filename>setegid.s</filename>:
102</para>
103
104<para><programlisting>
105        .globl  _setegid
106_setegid:
107        moveq   #47,d0
108        movl    #100,a0
109        moveq   #1,d1
110        movl    4(sp),a1
111        trap    #9
112        bccs    1$
113        jmp     cerror
1141$:
115        clrl    d0
116        rts
117</programlisting></para>
118
119<para>
120Put this in the file <filename>seteuid.s</filename>:
121</para>
122
123<para><programlisting>
124        .globl  _seteuid
125_seteuid:
126        moveq   #47,d0
127        movl    #100,a0
128        moveq   #0,d1
129        movl    4(sp),a1
130        trap    #9
131        bccs    1$
132        jmp     cerror
1331$:
134        clrl    d0
135        rts
136</programlisting></para>
137
138<para>
139After creating the files, you then assemble them using
140</para>
141
142<screen>
143&prompt;<userinput>as seteuid.s</userinput>
144&prompt;<userinput>as setegid.s</userinput>
145</screen>
146
147<para>
148which should produce the files <filename>seteuid.o</filename> and
149<filename>setegid.o</filename>.
150</para>
151
152<para>
153Next you need to add these to the LIBSM line in the DNIX section of
154the Samba Makefile. Your LIBSM line will look something like this:
155</para>
156
157<para><programlisting>
158LIBSM = setegid.o seteuid.o -ln
159</programlisting></para>
160
161<para>
162You should then remove the line:
163</para>
164
165<para><programlisting>
166#define NO_EID
167</programlisting></para>
168
169<para>from the DNIX section of <filename>includes.h</filename>.</para>
170
171</sect1>
172
173<sect1>
174<title>Red Hat Linux</title>
175
176<para>
177By default during installation, some versions of Red Hat Linux add an
178entry to <filename>/etc/hosts</filename> as follows:
179<programlisting>
180127.0.0.1 loopback "hostname"."domainname"
181</programlisting>
182</para>
183
184<para>
185<indexterm><primary>loopback interface</primary></indexterm>
186This causes Samba to loop back onto the loopback interface.
187The result is that Samba fails to communicate correctly with
188the world and therefore may fail to correctly negotiate who
189is the master browse list holder and who is the master browser.
190</para>
191
192<para>
193Corrective action: Delete the entry after the word "loopback"
194in the line starting 127.0.0.1.
195</para>
196</sect1>
197
198<sect1>
199<title>AIX: Sequential Read Ahead</title>
200<!-- From an email by William Jojo <jojowil@hvcc.edu> -->
201<para>
202Disabling sequential read ahead can improve Samba performance significantly
203when there is a relatively high level of multiprogramming (many smbd processes
204or mixed with another workload), not an abundance of physical memory or slower
205disk technology. These can cause AIX to have a higher WAIT values. Disabling
206sequential read-ahead can also have an adverse affect on other workloads in the
207system so you will need to evaluate other applications for impact.
208</para>
209
210<para>
211It is recommended to use the defaults provided by IBM, but if you experience a
212high amount of wait time, try disabling read-ahead with the following commands:
213</para>
214
215<para>
216For AIX 5.1 and earlier: <userinput>vmtune -r 0</userinput>
217</para>
218
219<para>
220For AIX 5.2 and later jfs filesystems: <userinput>ioo -o minpgahead=0</userinput>
221</para>
222
223<para>
224For AIX 5.2 and later jfs2 filesystems: <userinput>ioo -o j2_minPageReadAhead=0</userinput>
225</para>
226
227<para>
228If you have a mix of jfs and jfs2 filesystems on the same host, simply use both
229ioo commands.
230</para>
231</sect1>
232
233<sect1>
234<title>Solaris</title>
235
236<sect2>
237<title>Locking Improvements</title>
238
239<para>Some people have been experiencing problems with F_SETLKW64/fcntl 
240when running Samba on Solaris. The built-in file-locking mechanism was
241not scalable. Performance would degrade to the point where processes would
242get into loops of trying to lock a file. It would try a lock, then fail,
243then try again. The lock attempt was failing before the grant was
244occurring. The visible manifestation of this was a handful of
245processes stealing all of the CPU, and when they were trussed, they would
246be stuck in F_SETLKW64 loops.
247</para>
248
249<para>
250Please check with Sun support for current patches needed to fix this bug.
251The patch revision for 2.6 is 105181-34, for 8 is 108528-19, and for 9 is 112233-04.
252After the installation of these patches, it is recommended to reconfigure
253and rebuild Samba.
254</para>
255
256<para>Thanks to Joe Meslovich for reporting this.</para>
257
258</sect2>
259
260<sect2 id="winbind-solaris9">
261<title>Winbind on Solaris 9</title>
262<para>
263Nsswitch on Solaris 9 refuses to use the Winbind NSS module. This behavior
264is fixed by Sun in patch <ulink
265url="http://sunsolve.sun.com/search/advsearch.do?collection=PATCH&type=collections&max=50&language=en&queryKey5=112960;rev=14&toDocument=yes">112960-14</ulink>.
266</para>
267</sect2>
268</sect1>
269
270</chapter>
271