<HTML ><HEAD ><TITLE >Frequently Asked Questions (FAQ)</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.63 "><LINK REL="HOME" TITLE="HP HOWTO" HREF="index.html"><LINK REL="PREVIOUS" TITLE="Linux as an office server" HREF="linux-desktop.html"><LINK REL="NEXT" TITLE="Customer References " HREF="customers.html"><META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1"><META NAME="Author" CONTENT="Bruno Cornec"><META NAME="KeyWords" CONTENT="Linux,HP,HP-UX,Hewlett,Packard"></HEAD ><BODY CLASS="CHAPTER" BGCOLOR="#FFFFFF" TEXT="#000000" LINK="#0000FF" VLINK="#840084" ALINK="#0000FF" ><DIV CLASS="NAVHEADER" ><TABLE WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TH COLSPAN="3" ALIGN="center" >HP HOWTO: Configuration Guide and Use of HP Products under Linux (Version 0.94)</TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="bottom" ><A HREF="linux-desktop.html" ><IMG SRC="images/prev.png" BORDER="0" ALT="Previous"></A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="customers.html" ><IMG SRC="images/next.png" BORDER="0" ALT="Next"></A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><DIV CLASS="CHAPTER" ><H1 ><A NAME="FAQ" >Chapter 5. Frequently Asked Questions (FAQ)</A ></H1 ><DIV CLASS="QANDASET" ><DL ><DT >5.1. <A HREF="faq.html#AEN6899" ><EM >"What's new in kernel 2.2 ?"</EM ></A ></DT ><DT >5.2. <A HREF="faq.html#AEN6907" ><EM >"What's new in kernel 2.4 ?"</EM ></A ></DT ><DT >5.3. <A HREF="faq.html#R2GO" ><EM >"How to have more than 1 GB of RAM on my NetServer ?"</EM ></A ></DT ><DT >5.4. <A HREF="faq.html#AEN6928" ><EM >"How to have more than 128 MB of swap on my NetServer ?"</EM ></A ></DT ><DT >5.5. <A HREF="faq.html#AEN6935" ><EM >"How to use the other procesors of my NetServer ?"</EM ></A ></DT ><DT >5.6. <A HREF="faq.html#AEN6943" ><EM >"Is Linux Y2K compatible ?"</EM ></A ></DT ><DT >5.7. <A HREF="faq.html#AEN6950" ><EM >"How to increase the number of processes managed by the kernel ?"</EM ></A ></DT ><DT >5.8. <A HREF="faq.html#AEN6957" ><EM >"How to increase the number of loopback devices managed by the kernel ?"</EM ></A ></DT ><DT >5.9. <A HREF="faq.html#AEN6964" ><EM >"How to have files bigger than 2 GB on ext2 ?"</EM ></A ></DT ></DL ><DIV CLASS="QANDAENTRY" ><DIV CLASS="QUESTION" ><P ><A NAME="AEN6899" ></A ><B >5.1. </B ><EM >"What's new in kernel 2.2 ?"</EM ></P ></DIV ><DIV CLASS="ANSWER" ><P ><B > </B > Read <A HREF="http://linuxtoday.com/news_story.php3?ltsn=1999-01-26-015-05-NW-SM" TARGET="_top" >Wonderful World of Linux 2.2</A > or <A HREF="http://www.linux-france.org/article/sys/linux-2.2/Linux-2.2.html" TARGET="_top" >the same in french</A >.</P ></DIV ></DIV ><DIV CLASS="QANDAENTRY" ><DIV CLASS="QUESTION" ><P ><A NAME="AEN6907" ></A ><B >5.2. </B ><EM >"What's new in kernel 2.4 ?"</EM ></P ></DIV ><DIV CLASS="ANSWER" ><P ><B > </B > Read <A HREF="http://linuxtoday.com/news_story.php3?ltsn=2001-01-05-007-04-NW-LF-KN" TARGET="_top" >Wonderful World of Linux 2.4</A >.</P ></DIV ></DIV ><DIV CLASS="QANDAENTRY" ><DIV CLASS="QUESTION" ><P ><A NAME="R2GO" ></A ><B >5.3. </B ><EM >"How to have more than 1 GB of RAM on my NetServer ?"</EM ></P ></DIV ><DIV CLASS="ANSWER" ><P ><B > </B > The following information are adapted from the <A HREF="http://humbolt.geo.uu.nl/Linux-MM/more_than_1GB.shtml" TARGET="_top" >page</A > of Rik van Riel. They concern 2.0.x as well as 2.2.x kernels, and 2.4.x. </P ><P > First of all, the IA32 Intel architecture is limited by construction in its memory management to 4 GB. Space which should be divided into virtual memory and physical memory. Which means that if you choose to recognize more RAM, the maximum size for a program decreases. </P ><P > But Linux can't manage more than 1 GB by default. To go above that, in fact up to 2 GB today, because Linux can't manage more memory for the moment, you need to modify 2 files provided with kernel sources and recompile it. Those 2 sources are <TT CLASS="FILENAME" >/usr/src/linux/include/asm-i386/page.h</TT > and <TT CLASS="FILENAME" >/usr/src/linux/arch/i386/vmlinux.lds</TT >.</P ><P > From 2.0.37 and 2.2.12 kernels on, the patch was integrated in the kernel and may be activated when doing a <B CLASS="COMMAND" >make {menu,x}config</B >.</P ><P > The maximum Ram managed in the i386 version was ported to 64 GB after 2.3.23. </P ></DIV ></DIV ><DIV CLASS="QANDAENTRY" ><DIV CLASS="QUESTION" ><P ><A NAME="AEN6928" ></A ><B >5.4. </B ><EM >"How to have more than 128 MB of swap on my NetServer ?"</EM ></P ></DIV ><DIV CLASS="ANSWER" ><P ><B > </B > Up to the version 2.8x of the util-linux package, the <B CLASS="COMMAND" >mkswap</B > command could create swap partitions only up to 128 MB maximum. You then had to create as much partitions as necessary. Till the 2.9 version, included in standard in RedHat 6.0 and following distributions, it's possible to create directly swap partitions up to 2 GB and to 8 partitions. </P ></DIV ></DIV ><DIV CLASS="QANDAENTRY" ><DIV CLASS="QUESTION" ><P ><A NAME="AEN6935" ></A ><B >5.5. </B ><EM >"How to use the other procesors of my NetServer ?"</EM ></P ></DIV ><DIV CLASS="ANSWER" ><P ><B > </B > Multi-processing is supported by Linux operationnaly till the 2.0 version of the kernel. For a 2.0.x kernel, you have to recompile it and set up the SMP variable in the Makefile to 1. For a 2.2.x or 2.4.x kernel, you have to set it up during the <B CLASS="COMMAND" >make {menu,x}config</B >. For more details, please consult the <A HREF="http://www.irisa.fr/prive/mentre/smp-howto" TARGET="_top" >SMP-HOWTO</A >.</P ></DIV ></DIV ><DIV CLASS="QANDAENTRY" ><DIV CLASS="QUESTION" ><P ><A NAME="AEN6943" ></A ><B >5.6. </B ><EM >"Is Linux Y2K compatible ?"</EM ></P ></DIV ><DIV CLASS="ANSWER" ><P ><B > </B > Generally, Linux is Y2K compatible. For more information please consult the <A HREF="http://www.linux.org/help/beginner/year2000.html" TARGET="_top" >FAQ</A >.</P ></DIV ></DIV ><DIV CLASS="QANDAENTRY" ><DIV CLASS="QUESTION" ><P ><A NAME="AEN6950" ></A ><B >5.7. </B ><EM >"How to increase the number of processes managed by the kernel ?"</EM ></P ></DIV ><DIV CLASS="ANSWER" ><P ><B > </B > For 2.2.x kernels, you need to edit the file <TT CLASS="FILENAME" >/usr/src/linux/include/linux/tasks.h</TT >, modify the value of the constant NR_TASKS (512 by default) and set it to a value which doesn't exceed 4092 or 4090 if APM is configured. It could be useful to set MAX_TASKS_PER_USER at the same time to an appropriate value. Then recompile the kernel as usual. </P ></DIV ></DIV ><DIV CLASS="QANDAENTRY" ><DIV CLASS="QUESTION" ><P ><A NAME="AEN6957" ></A ><B >5.8. </B ><EM >"How to increase the number of loopback devices managed by the kernel ?"</EM ></P ></DIV ><DIV CLASS="ANSWER" ><P ><B > </B > You need to edit the file <TT CLASS="FILENAME" >/usr/src/linux/drivers/block/loop.c</TT >, For 2.2.x kernels, you need to modify the value of the constant MAXLOOP (8 by default). For 2.4.x kernels, you need to modify the value of the static int max_loop variable. Then recompile the kernel as usual. </P ></DIV ></DIV ><DIV CLASS="QANDAENTRY" ><DIV CLASS="QUESTION" ><P ><A NAME="AEN6964" ></A ><B >5.9. </B ><EM >"How to have files bigger than 2 GB on ext2 ?"</EM ></P ></DIV ><DIV CLASS="ANSWER" ><P ><B > </B > You need to have a kernel 2.4.x, glibc 2.1.3 at least and that all necessary tools have been recompiled. Look at <A HREF="http://www.suse.de/~aj/linux_lfs.html" TARGET="_top" >http://www.suse.de/~aj/linux_lfs.html</A > </P ></DIV ></DIV ></DIV ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="linux-desktop.html" ><IMG SRC="images/prev.png" BORDER="0" ALT="Previous"></A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" ><IMG SRC="images/home.png" BORDER="0" ALT="Home"></A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="customers.html" ><IMG SRC="images/next.png" BORDER="0" ALT="Next"></A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >Linux as an office server</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" > </TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >Customer References</TD ></TR ></TABLE ></DIV ></BODY ></HTML >