unx33.htm

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<CENTER><A ID="I29" NAME="I29">

<FONT SIZE=3><B>The </B><B><I>home</I></B><B> Slice</B>

<BR></FONT></A></CENTER></H5>

<P>This is where the user's login directories are placed. Making home its own slice prevents users from hurting anything else if they run this file system out of space.

<BR></P>

<P>A good starting point for this slice is 1 MB per application user plus 5 MB per power user and 10 MB per developer you intend to support on this system.

<BR></P>

<HR ALIGN=CENTER>

<NOTE>

<IMG SRC="imp.gif" WIDTH = 68 HEIGHT = 35><B>TIP: </B>Don't worry too much about getting it exactly right. If you need more space for a particular user, just move that user's directory to a different file system that does have room and create a symbolic 
link in /home to point to its new location. The user may never know you moved the directory.

<BR></NOTE>

<HR ALIGN=CENTER>

<H5 ALIGN="CENTER">

<CENTER><A ID="I30" NAME="I30">

<FONT SIZE=3><B>The </B><B><I>tmp</I></B><B> Slice</B>

<BR></FONT></A></CENTER></H5>

<P>Large temporary files are placed in /var/tmp but sufficient temporary files are placed in /tmp that you don't want it to run your root file system out of space. If your users are mostly application users, 5&#151;10 MB is sufficient for this slice. If 
they are power users or developers, 10-20 MB is better. If there are more than 10 users on the system at once, consider doubling the size of this slice.

<BR></P>

<HR ALIGN=CENTER>

<NOTE>

<IMG SRC="imp.gif" WIDTH = 68 HEIGHT = 35><B>TIP: </B>The files in the /tmp directory are very short-lived. Use the file system type TMPFS (Tmp file system, a ram based file system) for /tmp if your version of UNIX offers it. It can improve performance by 

placing this file system in RAM instead of on the disk. Losing the files on each reboot is not a concern, as UNIX clears the /tmp directory on each reboot anyway.

<BR></NOTE>

<HR ALIGN=CENTER>

<P>The disk label that contains the disk layout is held in block 0 of the disk. UNIX does not use this block in file systems, so there is no danger of overwriting it if a file system is located as the first slice on a disk. However, if a raw slice is the 
first slice, the application that uses the slice may overwrite block 0. Doing so will lose the label and make the disk inaccessible.

<BR></P>

<P>To prevent this, do the following: Make a file system the first slice (the one that contains block 0 of the disk drive). Skip cylinder 0 in assigning the space on the disk drive. It may waste one cylinder, but you won't lose your data.

<BR></P>

<H5 ALIGN="CENTER">

<CENTER><A ID="I31" NAME="I31">

<FONT SIZE=3><B>Assigning Slices to Disk Drives</B>

<BR></FONT></A></CENTER></H5>

<P>If you have more than one disk drive, a second decision you have is on which drive to place the slices. The goal is to balance the disk accesses between all of the drives. If you have two drives, consider the following split:

<BR></P>

<TABLE BORDER>

<TR>

<TD>

<P>Drive 1</P>

<TD>

<P>Drive 2</P>

<TR>

<TD>

<P>root</P>

<TD>

<P>var</P>

<TR>

<TD>

<P>swap</P>

<TD>

<P>opt</P>

<TR>

<TD>

<P>usr</P>

<TD>

<P>home</P></TABLE>

<P>The remaining slices split over the drives as space allows.

<BR></P>

<H4 ALIGN="CENTER">

<CENTER><A ID="I32" NAME="I32">

<FONT SIZE=3><B>Assigning IP (network) Addresses</B>

<BR></FONT></A></CENTER></H4>

<P>If the system has a network connection, it will need to be assigned an IP address. IP addresses are explained in Chapter 37. An IP address is a set of four numbers separated by dots, called a dotted quad. Each network connection has its own IP address. 

Within a LAN segment, usually the first three octets of the dotted quad will be the same. The fourth must be unique for each interface. The addresses 0 and 255 (all zeros and all ones) are reserved for broadcast addresses. The remaining 254 addresses may 
be assigned to any system.

<BR></P>

<HR ALIGN=CENTER>

<NOTE>

<IMG SRC="note.gif" WIDTH = 35 HEIGHT = 35><B>NOTE:</B> The IP address is not the EtherNet address. An EtherNet address is a hardware-level address assigned by the manufacturer. It is six octets long (48 bits). The first three represent the manufacturer of 

the network interface board. The remaining three octets are unique to the system. An IP address is a software level address. Part of the IP protocol, also called ARP or Address Resolution Protocol, is used to match the software IP address with the physical 

EtherNet address.

<BR></NOTE>

<HR ALIGN=CENTER>

<P>If this is your first system, you must decide on the first three octets as well. See Chapter 37 for applying for a network number. The number should be unique within the world and is obtainable at no cost.

<BR></P>

<P>If this is not the first system, then any unused value for the fourth octet can be used for this system.

<BR></P>

<H5 ALIGN="CENTER">

<CENTER><A ID="I33" NAME="I33">

<FONT SIZE=3><B>Do You Have the Needed Network Connections?</B>

<BR></FONT></A></CENTER></H5>

<P>Now is the time to check that you have a network connection for each network interface. Now is the time to check that you have the proper cables, transceivers (if needed), and connectors.

<BR></P>

<P>EtherNet comes in three varieties: thick (10Base5), thin (10Base2), and twisted pair (10BaseT). UNIX Systems come with some combination of three types of EtherNet connections: AUI, BNC, or RJ45. If your system has multiple connector types, they are all 

for the same network interface, unless you purchased an add-on interface that uses a connector type different from that of the main system. Using the matrix below, you can see which parts you need:

<BR></P>

<TABLE BORDER>

<TR>

<TD COLSPAN=2>

<PRE>

<BR>Connector

<BR></PRE>

<TD COLSPAN=2>

<PRE>

<BR>Network Type

<BR></PRE>

<TR>

<TD>

<PRE>

<BR>Type

<BR></PRE>

<TD>

<PRE>

<BR>10Base5

<BR></PRE>

<TD>

<PRE>

<BR>10Base2

<BR></PRE>

<TD>

<PRE>

<BR>10BaseT

<BR></PRE>

<TR>

<TD>

<PRE>

<BR>AUI

<BR></PRE>

<TD>

<PRE>

<BR>AUI cable

<BR></PRE>

<TD>

<PRE>

<BR>AUI to BNC

<BR></PRE>

<TD>

<PRE>

<BR>AUI to RJ45

<BR></PRE>

<TR>

<TD>

<PRE>

<BR><BR>

<BR></PRE>

<TD>

<PRE>

<BR>and transceiver

<BR></PRE>

<TD>

<PRE>

<BR>transceiver

<BR></PRE>

<TD>

<PRE>

<BR>transceiver

<BR></PRE>

<TR>

<TD>

<PRE>

<BR>BNC

<BR></PRE>

<TD>

<PRE>

<BR>10Base2 Hub

<BR></PRE>

<TD>

<PRE>

<BR>BNC Tee

<BR></PRE>

<TD>

<PRE>

<BR>10Base2 Hub

<BR></PRE>

<TR>

<TD>

<PRE>

<BR>RJ45

<BR></PRE>

<TD>

<PRE>

<BR>10BaseT Hub

<BR></PRE>

<TD>

<PRE>

<BR>10BaseT Hub

<BR></PRE>

<TD>

<PRE>

<BR>RJ45 Cable

<BR></PRE>

<TR>

<TD>

<PRE>

<BR><BR>

<BR></PRE>

<TD>

<PRE>

<BR>with AUI port

<BR></PRE>

<TD>

<PRE>

<BR>with BNC port

<BR></PRE>

<TD>

<PRE>

<BR>and free slot

<BR></PRE>

<TR>

<TD>

<PRE>

<BR><BR>

<BR></PRE>

<TD>

<PRE>

<BR>and RJ45 Cable

<BR></PRE>

<TD>

<PRE>