freebsd-nq/share/doc/handbook/diskless.sgml
1997-02-22 13:06:56 +00:00

164 lines
5.3 KiB
Plaintext

<!-- $Id$ -->
<!-- The FreeBSD Documentation Project -->
<sect><heading>Diskless operation<label id="diskless"></heading>
<p><em>Contributed by &a.martin;.</em>
<tt>netboot.com/netboot.rom</tt> allow you to boot your
FreeBSD machine over the network and run FreeBSD without
having a disk on your client. Under 2.0 it is now
possible to have local swap. Swapping over NFS is also
still supported.
Supported Ethernet cards include: Western Digital/SMC
8003, 8013, 8216 and compatibles; NE1000/NE2000 and
compatibles (requires recompile)
<sect1>
<heading>Setup Instructions</heading>
<p><enum>
<item> Find a machine that will be your server. This
machine will require enough disk space to hold the
FreeBSD 2.0 binaries and have bootp, tftp and NFS
services available.
Tested machines:
<itemize>
<item>HP9000/8xx running HP-UX 9.04 or later (pre
9.04 doesn't work)</item>
<item>Sun/Solaris 2.3. (you may need to get
bootp)</item>
</itemize>
<item>Set up a bootp server to provide the client with
IP, gateway, netmask.
<tscreen><verb>
diskless:\
:ht=ether:\
:ha=0000c01f848a:\
:sm=255.255.255.0:\
:hn:\
:ds=192.1.2.3:\
:ip=192.1.2.4:\
:gw=192.1.2.5:\
:vm=rfc1048:
</verb></tscreen></item>
<item>Set up a TFTP server (on same machine as bootp
server) to provide booting information to client.
The name of this file is <tt>cfg.X.X.X.X</tt> (or
<tt>/tftpboot/cfg.X.X.X.X</tt>, it will try both)
where <tt>X.X.X.X</tt> is the IP address of the
client. The contents of this file can be any valid
netboot commands. Under 2.0, netboot has the
following commands:
<tscreen><verb>
help - print help list
ip <X.X.X.X> - print/set client's IP address
server <X.X.X.X> - print/set bootp/tftp server address
netmask <X.X.X.X> - print/set netmask
hostname <name> - print/set hostname
kernel <name> - print/set kernel name
rootfs <ip:/fs> - print/set root filesystem
swapfs <ip:/fs> - print/set swap filesystem
swapsize <size> - set diskless swapsize in Kbytes
diskboot - boot from disk
autoboot - continue boot process
trans <on|off> - turn transceiver on|off
flags [bcdhsv] - set boot flags
</verb></tscreen>
A typical completely diskless cfg file might contain:
<tscreen><verb>
rootfs 192.1.2.3:/rootfs/myclient
swapfs 192.1.2.3:/swapfs
swapsize 20000
hostname myclient.mydomain
</verb></tscreen>
A cfg file for a machine with local swap might contain:
<tscreen><verb>
rootfs 192.1.2.3:/rootfs/myclient
hostname myclient.mydomain
</verb></tscreen>
<item>Ensure that your NFS server has exported the root
(and swap if applicable) filesystems to your client,
and that the client has root access to these
filesystems
A typical <tt>/etc/exports</tt> file on FreeBSD might
look like:
<tscreen><verb>
/rootfs/myclient -maproot=0:0 myclient.mydomain
/swapfs -maproot=0:0 myclient.mydomain
</verb></tscreen>
And on HP-UX:
<tscreen><verb>
/rootfs/myclient -root=myclient.mydomain
/swapfs -root=myclient.mydomain
</verb></tscreen>
<item>If you are swapping over NFS (completely diskless
configuration) create a swap file for your client
using <tt>dd</tt>. If your <tt>swapfs</tt> command has the
arguments <tt>/swapfs</tt> and the size 20000 as in the
example above, the swapfile for myclient will be called
<tt>/swapfs/swap.X.X.X.X</tt> where <tt>X.X.X.X</tt>
is the client's IP addr, eg:
<tscreen><verb>
# dd if=/dev/zero of=/swapfs/swap.192.1.2.4 bs=1k count=20000
</verb></tscreen>
Also, the client's swap space might contain sensitive
information once swapping starts, so make sure to
restrict read and write access to this file to prevent
unauthorized access:
<tscreen><verb>
# chmod 0600 /swapfs/swap.192.1.2.4
</verb></tscreen>
<item> Unpack the root filesystem in the directory the
client will use for its root filesystem
(<tt>/rootfs/myclient</tt> in the example above).
<itemize>
<item> On HP-UX systems: The server should be
running HP-UX 9.04 or later for HP9000/800 series
machines. Prior versions do not allow the
creation of device files over NFS.
<item> When extracting <tt>/dev</tt> in
<tt>/rootfs/myclient</tt>, beware that some
systems (HPUX) will not create device files that
FreeBSD is happy with. You may have to go to
single user mode on the first bootup (press
control-c during the bootup phase), cd
<tt>/dev</tt> and do a "<tt>sh ./MAKEDEV
all</tt>" from the client to fix this.
</itemize>
<item>Run <tt>netboot.com</tt> on the client or make an EPROM
from the <tt>netboot.rom</tt> file
</enum>
<sect1>
<heading>Using Shared <tt>/</tt> and <tt>/usr</tt> filesystems</heading>
<p>At present there isn't an officially sanctioned way of
doing this, although I have been using a shared <tt>/usr</tt>
filesystem and individual <tt>/</tt> filesystems for each client.
If anyone has any suggestions on how to do this cleanly,
please let me and/or the &a.core; know.
<sect1>
<heading>Compiling netboot for specific setups</heading>
<p>Netboot can be compiled to support NE1000/2000 cards by
changing the configuration in
<tt>/sys/i386/boot/netboot/Makefile</tt>. See the
comments at the top of this file.