README.BOOTP revision 130786
1IMPORTANT NOTE: 2 3As of Feb. 11, 2002 (and indeed, for quite some time before that), 4the /etc/rc.diskless{1,2} scripts support a slightly different 5diskless boot process than the one documented in the rest of 6this file (which is 3 years old). 7 8I am not deleting the information below because it contains some 9useful background information on diskless operation, but for the 10actual details you should look at /etc/rc.diskless1, /etc/rc.diskless2, 11and the /usr/share/examples/diskless/clone_root script which can 12be useful to set up clients and server for diskless boot. 13 14--- $FreeBSD: head/share/examples/diskless/README.BOOTP 130786 2004-06-20 13:17:37Z mpp $ --- 15------------------------------------------------------------------------ 16 17 BOOTP configuration mechanism 18 19 Matthew Dillon 20 dillon@backplane.com 21 22 BOOTP kernels automatically configure the machine's IP address, netmask, 23 optional NFS based swap, and NFS based root mount. The NFS server will 24 typically export a shared read-only /, /usr, and /var to any number of 25 workstations. The shared read-only root is typically either the server's 26 own root or, if you are more security conscious, a contrived root. 27 28 The key issue with starting up a BOOTP kernel is that you typically want 29 to export read-only NFS partitions from the server, yet still be able to 30 customize each workstation ( or not ). 31 32 /etc/rc.diskless1 is responsible for doing core mounts and for retargeting 33 /conf/ME ( part of the read-only root NFS mount ) to /conf/$IP_OF_CLIENT. 34 /etc/rc.conf.local and /etc/rc.local, along with other machine-specific 35 configuration files, are typically softlinks to /conf/ME/<filename>. 36 37 In the BOOTP workstation /conf/$IP/rc.conf.local, you must typically 38 turn *OFF* most of the system option defaults in /etc/rc.conf as well 39 as do additional custom configuration of your environment 40 41 The /usr/src/share/examples/diskless directory contains a typical 42 X session / sshd based workstation configuration. The directories 43 involved are HT.DISKLESS/ and 192.157.86.12/. 44 45 Essentially, the $IP/ directory ( which rc.diskless looks for in 46 /conf/$IP/ ) contains all the junk. The HT.DISKLESS directory exists 47 to hold common elements of your custom configuration so you do not have 48 to repeat those elements for each workstation. The example /conf 49 structure included here shows how to create a working sshd setup ( so 50 you can sshd into the diskless workstation ), retarget xdm's pid and error 51 files to R+W directories if /usr is mounted read-only, and retarget 52 syslogd and other programs. This example is not designed to run out of 53 the box and some modifications are required. 54 55 >> NOTE << HT.DISKLESS/ttys contains the typical configuration required 56 to bring X up at boot time. Essentially, it runs xdm in the foreground 57 with the appropriate arguments rather then a getty on ttyv0. You must 58 run xdm on ttyv0 in order to prevent xdm racing with getty on a virtual 59 terminal. Such a race can cause your keyboard to be directed away from 60 the X session, essentially making the session unusable. 61 62 Typically you should start with a clean slate by tar-copying this example 63 directory to /conf and then hack on it in /conf rather then in 64 /usr/share/examples/diskless. 65 66 BOOTP CLIENT SETUP 67 68 Here is a typical kernel configuration. If you have only one ethernet 69 interface you do not need to wire BOOTP to a specific interface name. 70 BOOTP requires NFS and NFS_ROOT, and our boot scripts require MFS. If 71 your /tmp is *not* a softlink to /var/tmp, the scripts also require NULLFS 72 73# BootP 74# 75options BOOTP # Use BOOTP to obtain IP address/hostname 76options BOOTP_NFSROOT # NFS mount root filesystem using BOOTP info 77options "BOOTP_NFSV3" # Use NFS v3 to NFS mount rootoptions 78options BOOTP_COMPAT # Workaround for broken bootp daemons. 79#options "BOOTP_WIRED_TO=de0" 80 81options MFS # Memory File System 82options NFS # Network Filesystem 83options NFS_ROOT # Nfs can be root 84options NULLFS # nullfs to map /var/tmp to /tmp 85 86 BOOTP SERVER SETUP 87 88 The BOOTP server must be running on the same logical LAN as the the 89 BOOTP client(s). You need to setup two things: 90 91 (1) You need to NFS-export /, /usr, and /var. 92 93 (2) You need to run a BOOTP server. DHCPD can do this. 94 95 96 NFS Export: 97 98 Here is an example "/etc/exports" file. 99 100/ -ro -maproot=root: -network 192.157.86.0 -mask 255.255.255.192 101/usr -ro -maproot=root: -network 192.157.86.0 -mask 255.255.255.192 102/var -ro -maproot=root: -network 192.157.86.0 -mask 255.255.255.192 103 104 In order to be an NFS server, the server must run portmap, mountd, 105 nfsd, and rpc.statd. The standard NFS server options in /etc/rc.conf 106 will work ( you should put your overrides in /etc/rc.conf.local on the 107 server and not edit the distribution /etc/rc.conf, though ). 108 109 BOOTP Server: 110 111 This configuration file "/etc/dhcpd.conf" example is for 112 the '/usr/ports/net/isc-dhcp' dhcpd port. 113 114 subnet 192.157.86.0 netmask 255.255.255.192 { 115 # range if you want to run the core dhcpd service of 116 # dynamic IP assignment, but it is not used with BOOTP 117 # workstations 118 range 192.157.86.32 192.157.86.62; 119 120 # misc configuration. 121 # 122 option routers 192.157.86.2; 123 option domain-name-servers 192.157.86.2; 124 125 server-name "apollo.fubar.com"; 126 option subnet-mask 255.255.255.192; 127 option domain-name-servers 192.157.86.2; 128 option domain-name "fubar.com"; 129 option broadcast-address 192.157.86.63; 130 option routers 192.157.86.2; 131 } 132 133 host test1 { 134 hardware ethernet 00:a0:c9:d3:38:25; 135 fixed-address 192.157.86.11; 136 option root-path "192.157.86.2:/"; 137 option option-128 "192.157.86.2:/images/swap"; 138 } 139 140 host test2 { 141 # hardware ethernet 00:e0:29:1d:16:09; 142 hardware ethernet 00:10:5a:a8:94:0e; 143 fixed-address 192.157.86.12; 144 option root-path "192.157.86.2:/"; 145 option option-128 "192.157.86.2:/images/swap"; 146 } 147 148 SWAP. This example includes options to automatically BOOTP configure 149 NFS swap on each workstation. In order to use this capabilities you 150 need to NFS-export a swap directory READ+WRITE to the workstations. 151 152 You must then create a swap directory for each workstation you wish to 153 assign swap to. In this example I created a dummy user 'lander' and 154 did an NFS export of /images/swap enforcing a UID of 'lander' for 155 all accesses. 156 157 apollo:/usr/ports/net# ls -la /images/swap 158 total 491786 159 drwxr-xr-x 2 root wheel 512 Dec 28 07:00 . 160 drwxr-xr-x 8 root wheel 512 Jan 20 10:54 .. 161 -rw-r--r-- 1 lander wheel 33554432 Dec 23 14:35 swap.192.157.86.11 162 -rw-r--r-- 1 lander wheel 335544320 Jan 24 16:55 swap.192.157.86.12 163 -rw-r--r-- 1 lander wheel 134217728 Jan 21 17:19 swap.192.157.86.6 164 165 A swap file is best created with dd: 166 167 # create a 32MB swap file for a BOOTP workstation 168 dd if=/dev/zero of=swap.IPADDRESS bs=1m count=32 169 170 It is generally a good idea to give your workstations some swap space, 171 but not a requirement if they have a lot of memory. 172 173