ralphs@netwinder.org
etc/fstab
etc/fstab
etc/mtab
/proc, /mnt
There are a variety of reasons you'd want to update the hard disk image on your NetWinder. From a simple update to a newer disk image, to a forced reinstallation because something went badly wrong, this manual covers the various possibilities.
Each chapter in this manual covers a different installation method. Consult the section `Choosing an installation method' below for advice on how to determine the best method for your particular circumstances. There is a general `Troubleshooting' chapter at the end.
Official disk images for the NetWinder can be downloaded from
ftp://ftp.netwinder.org/pub/netwinder/images/ directory (older disk
images are in /pub/ccc/images/ instead). For more information
about the various disk images, please see
http://www.netwinder.org/~ralphs/diskimage.html.
There are also some unofficial disk images that may be of interest. Having not tried them myself, I withold further comments and will only say that there is an ongoing port of Debian (see http://www.debian.org/ports/arm/) and there is also a RedHat port with versioned glibc called Titan (see http://www.nw.carleton.ca).
A variety of installation methods can be used to update the NetWinder's disk. Which one is right for you will depend on such factors as how much free space you have on the NetWinder's hard disk, what type of network connection you have got, etc. The following paragraphs are intended to asist you in selecting an appropriate installation method.
For the OfficeServer and DM built 15, a "rescue partition" is included on
/dev/hda4. It contains a small filesystem that provides facilities
to restore the rest of the drive from either a Windows or Unix host, without
having to worry about nfs booting. Use of this new rescue system is covered
in the
Rescue-HOWTO.html.
For people with plenty of free disk space, this is the easiest method. You download the compressed disk image (tarball) onto your NetWinder, then expand it onto a free partition. Requires enough space to hold the compressed and uncompressed images simultaneously (about 900 MB for build #12).
The compressed tarball can be downloaded to another machine and be expanded from there across a (local) network connection. The `other' machine must support NFS file sharing (unix machine) or SMB file sharing (Windows) and must have enough room to hold the compressed disk image. The NetWinder must have enough room for the uncompressed image (ideally on an unused partition).
You can remove the hard disk from the NetWinder and install it in an ordinary PC. This will of course void your warrantee! You'll need a laptop IDE adaptor cable, available at most computer stores, since the connector is physically smaller. Then you can set the drive as slave and format/install to your hearts content from the host PC system.
If you own a parallel-port device such as the Backpack CD-ROM or a tape drive, you can use this to hold the disk image. The NetWinder can even boot off the cd-rom drive (it takes forever, since the parallel port is fairly slow). You can also use ZIP drives, though you won't be able to fit an entire disk image onto one of course. Still useful for emergency booting though.
Certain versions of the NetWinder firmware come with a `rescue' filesystem that allows the machine to be booted without using the hard disk or the network connection. It turns your NetWinder into an NFS server, so that another computer on your network can connect to it and decompress the disk image. This method requires a second (unix) machine as an NFS client, with enough room to hold the compressed disk image.
The NetWinder can boot from another server (typically another Linux machine) using TFTP to fetch the kernel and NFS to access the root filesystem. It can be quite tricky to get this setup, so this option is not recommended for novices. It requires a second computer with enough room for the compressed and uncompressed disk image, and it must have tftp and nfs server support.
Mike Montour has developed a trimmed-down and more automatic method similar to the NFS booting technique, but without the overhead of an entire disk image on the rescue server. His latest version also includes a GUI tool to help set up the server for tftp, nfs, and dhcp services. This method also requires a second (unix) machine that can support network booting.
The chapter describes the basic method for installing a new diskimage on a NetWinder. The methods described in the other chapters are variations on the basic method, so this chapter makes for good background reading even if you are using one of the other methods. See the first chapter for an overview of the different installation methods.
This is the simplest method but requires considerable hard drive space - enough to hold the compressed disk image (about 250 MB for build #12) as well as the uncompressed image (about 650 MB). Add to this the space occupied by the existing disk image, and you'll see that this method is practical only on machines with hard disks of 2 GB or more capacity.
A new disk image is also required, of course. It can be downloaded (via
FTP) from netwinder.org as a tar.gz archive. Alternatively you
might have received the image on CDROM or other media; you should transfer
the image onto the NetWinder by some means - FTP, NFS, SMB, HTTP - keep in
mind that the image is a binary file.
Some manipulation may be required to free up space on the partition where the new image is to be installed. While it is not strictly necessary for the partition to be empty, subtle problems can arise if old files are mixed with the new image. We recommend clearing the partition completely to avoid trouble. See also section 4.3 for more information on how to free up a partition.
The df command will allow you to check disk usage. Typical output
from this command is shown below. Don't be alarmed if the values reported
by your system differ.
Filesystem 1024-blocks Used Available Capacity Mounted on
/dev/hda1 1014784 645694 316651 67% /
/dev/hda3 2792760 72888 2575451 3% /home
Here we see that the third partition /dev/hda3 contains only 72 MB
of data, whereas there remain 316 MB of free space on the first partition
/dev/hda1. If we moved the data from the third partition into the
first, then /dev/hda3 would be empty and we could install the new
diskimage there. Since unix doesn't allow files to be moved across
filesystems, we first copy the data from /dev/hda3 and later delete
it. You must be root to run these commands of course.
cd /
umount /dev/hda3
mount /dev/hda3 /mnt/hda3
cp -ax /mnt/hda3/. /home
umount /dev/hda3
The data has now been copied to the /home directory, which is now
on /dev/hda1. To prevent side effects, you should also edit the
/etc/fstab file and comment out the line beginning with
/dev/hda3, or delete the entire line. Otherwise, your system may
have difficulty trying to mount /dev/hda3 next time you reboot.
The free partition can now be cleared out, either by formatting it or by
deleting all the files (rm -rf). Again this isn't strictly
necessary but it is recommended. Be sure you give the right partition
number otherwise you'll end up formatting the wrong partition. The
commands for formatting the third partition, and then mounting it on
/mnt/hda3, are as follows.
mke2fs /dev/hda3
mount /dev/hda3 /mnt/hda3
Now you're ready to install the new disk image onto /mnt/hda3. You
can use the df command to verify the amount of free space if you
wish.
Special note: If you are running dm-3.1-15 disk image, then you
must pass extra flags to mke2fs otherwise the firmware and kernel
won't recognize your filesystem correctly. To format a partition you should
use these commands
mke2fs -O sparse_super /dev/hda3
To install the image, use the tar command to extract files from the
compressed image. If you have not yet downloaded the image, do so now
(placing it wherever there is enough room). Then use the following commands
to expand the archive. The example assumes that your "empty" partition has
been mounted on /mnt/hda3 (as in the previous section):
cd /mnt/hda3
tar zxpf YourImage.tar.gz
Replace YourImage with the name of the image you downloaded
(including the full path, if it's not located in the current directory).
This process will take 5 to 10 minutes, on average.
etc/fstab
The etc/fstab file will need to be edited before the new image can be
booted. Using your favourite text editor, open the file
/mnt/hda3/etc/fstab. The line that begins with /dev/hda3
should be deleted or commented out. The line that begins with
/dev/hda1 should then be changed so that it begins with
/dev/hda3 (or whichever partition you've just installed to). Save
the modified file and exit the editor. Then unmount the partition in
anticipation of rebooting:
sync
cd /
umount /mnt/hda3
While it should not be necessary with official disk images, you might want
to check that the file etc/mtab does not exist in your
image (before you unmount it). Delete this file if it does exist (for
example, rm /mnt/hda3/etc/mtab).
The last step is to change the firmware settings so as to boot from the new
partition. Reboot the machine (using CTRL-ALT-DEL for example) and then
upon reboot, at the `Press any key to abort autoboot' prompt, press a key.
Enter the following commands to switch over to /dev/hda3:
load-defaults
setenv kerndev /dev/hda3
setenv rootdev /dev/hda3
save-all
boot
The save-all command may be omitted if you just want to test boot
the new image (you can re-issue it later on). See the Firmware-HOWTO at
http://www.netwinder.org/~ralphs/howto/Firmware-HOWTO.html for
more information.
The new disk image should now boot. If not, consult the Troubleshooting chapter at the end of this manual. To access your old disk image (perhaps to copy out some personal files, for example) you can mount it with a command like:
mount /dev/hda1 /mnt
This chapter describes a slight variation on the basic method for installing a new disk image on a NetWinder. It is useful if there is not enough disk space on the NetWinder to hold both the compressed and uncompressed images.
This method requires sufficient space on the NetWinder to stored the new,
uncompressed disk image (about 650 MB for build #12). The NetWinder must
also have network connectivity (ethernet) - the nwconfig program
can used to configure IP address and other parameters.
In addition, a second computer is needed to hold the compressed disk image (about 250 MB). This can be another unix machine, or a Windows machine - anything capable of communicating with the NetWinder via ethernet. Configuration of the remote system is not covered in much detail here.
On the NetWinder, a disk partition should be freed up. This process is
described in detail in section 2.2 of the previous chapter. In the
following examples, it will be assumed that an empty partition has been
mounted on /mnt/hda3.
The `other computer' (hereafter called the server) also needs to be set up.
The compressed disk image should be downloaded to this server machine. The
image should then be made available to the NetWinder by putting it into an
NFS share (for unix systems) or into a public folder (for Windows machines).
Unix shares are normally listed in the /etc/exports file, while
Windows handles it by right-clicking on the directory name and changing the
properties.
The NetWinder must then be configured for access to the (remote) compressed disk image. The process depends on the type of server being used.
The following commands show how to mount a remote NFS server so that theNetWinder can access its files. Replace 192.168.1.2 with the IP
address of the server and replace /exportname with the actual name
of the exported filesystem. This must match the name given in the
/etc/exports file on the server.
mkdir /mnt/server
mount 192.168.1.2:/exportname /mnt/server
To verify proper operation, use the command ls /mnt/server - you
should see the compressed disk image in the listing.
In the case of a Windows machine acting as the server, you will have created
a shared folder with a name such as SHARE. You can access this share from
your NetWinder using the smbmount command. Substitute the Windows
computer's name for COMPUTER, and specify your windows USERNAME and
WORKGROUP as well. You'll be prompted for your password.
mkdir /mnt/server
smbmount //COMPUTER/SHARE /mnt/server -U USERNAME -W WORKGROUP
In case of difficulty, consult the smbmount man page. To verify
that it is working correctly, enter the command ls /mnt/server -
you should see the compressed disk image in the listing.
The proceedure for installing the image is nearly the same as that described in the basic method, except that the image now streams over the ethernet from the server system. The commands for installation are as follows.
cd /mnt/hda3
tar zxpf /mnt/server/YourImage.tar.gz
Replace YourImage with the name of the compressed disk image that
you downloaded to the server. The process will nominally take about 10
minutes, but it depends on how much traffic is on the network. You can
monitor progress by switching to another terminal or window and using the
df command.
Please refer to sections 2.4 and 2.5 in the previous chapter for the post-installation instructions. Note that it is essential to update the etc/fstab file before attempting to boot the new image.
This chapter describes how to install a new diskimage on a NetWinder by removing the hard disk and installing it as the slave drive in another system. This method is not recommended since it will void the warrantee, but its a practical method especially for those people with very small hard disks.
This method requires a second computer where the NetWinder's hard disk can be installed. The second machine could be another NetWinder, or an ordinary PC running some form of unix. In the case of a regular PC, an adaptor cable is required since the NetWinder hard drive is of the 2.5" laptop variety, which will not plug directly into the normal IDE connectors. Adaptors are available at most computer stores for about $10.
Static electricity can kill a NetWinder! Be sure to be properly grounded before you start poking around inside your computer.
The NetWinder's hard drive should be connected to the host computers IDE controller, and (possibly) the master/slave jumper will need to be adjusted on the NetWinder's drive. To gain access to the drive, open the four screws on the bottom of the NetWinder. Usually it's possible to move the NetWinder close enough to the PC so that the cable can be directly connected, if not, you'll have to remove the hard drive itself (the screws are on the bottom of the motherboard).
Once the drive is connected, the PC can be powered up. Do whatever is
necessary for the drive to be detected (this might mean going into the BIOS
and specifying the drive parameters, or on modern PC's, the drive will be
auto-detected). I'll assume for the purpose of this example that the PC's
main hard drive is /dev/hda and that the NetWinder's drive is
/dev/hdb - but you'll have to verify that this is the case on your
machine (use the dmesg command for this).
There must be enough room to install the new disk image on the NetWinder's drive. You have the option of moving/deleting files to free up a partition, or you might choose to format the NetWinder's hard disk completely and repartition it as you wish. I cannot give you a step-by-step guide here, so I'll describe the available options and let you decide.
To transfer files between partitions, you need to mount both partitions and
then use the cp and rm commands. Two mountpoints are
required for this - you can use any two directories - for example
/mnt/one and /mnt/two. Of course the directories must
exist before they can be used, so go wild with the mkdir command.
Then mount the two partitions (picking on /dev/hdb1 and
/dev/hdb2 for this example):
mount /dev/hdb1 /mnt/one
mount /dev/hdb2 /mnt/two
Now files can be copied from /mnt/one to /mnt/two (or
vice-versa) using the cp command. To remove the originals after
they've been copied, use the rm command. When you're done, unmount
the partitions again:
sync
umount /mnt/one
umount /mnt/two
Once a partition has been cleared of files, or if you don't want to keep the old files, the format command can be used to initialize a new filesystem. This will completely wipe out everything on the partition, with no way to restore it. Use with care, and check very carefully that the correct partition and drive are specified.
mke2fs /dev/hdb1
The preceeding example will format the first partition on the second (slave)
drive, presumably the NetWinder drive. In case you're not clear on the
naming convention yet, the drives are called /dev/hdXY where X is a
letter (a for the first drive, b for the second, etc) and
Y is a number indicating the partition (starting from one).
In some cases it may be desirable to repartition the entire drive, for example if you are updating an old system and don't want to keep the old version anyhow. Note that after repartitioning, you must format the partitions, and this will destroy all data on the drive.
To adjust the partition tables, use the fdisk command. You have
to tell it which drive you want to repartition - for example say fdisk
/dev/hdb to adjust the partition table on the second (slave) drive.
The rest of the commands (for deleting a partition, creating a new one, etc)
are explained in the on-line help. There is also a nice man page (man
fdisk) that gives more information.
The recommended disk layout is as follows: the first partition is the root
filesystem (type 83, Linux) usually about 1 GB in size. The second
partition is used for swap (type 82, Linux swap) and is 64 to 128 MB in
size. Anything remaining space is allocated to third partition and gets
mounted as /home.
To install the image, you need to ensure that both the source and
destination partitions are mounted, then you can use the tar
command to extract files from the diskimage. Most likely, the diskimage is
located on your main disk (hda) and the destination is the first partition
on hdb. In this case, the appropriate commands are as follows:
mount /dev/hdb1 /mnt/hdb1
cd /mnt/hdb1
tar zxpf /path/to/YourImage.tar.gz
You'll need to ensure that the mountpoint /dev/hdb1 exists (or use
a different name), and you'll need to specify an appropriate path and
filname instead of path/to/YourImage. This process should be
pretty quick, about 5-10 minutes, since the data is moving over the IDE bus
directly.
After the installation of the disk image is completed, be sure to review the
etc/fstab file in the installed image. The entries in this file
must correspond with the way the partitions are used, eg. if the first
partition contains the main image, then it should be mounted as /
in the fstab file. Keep in mind that the drive names listed in the fstab
file should be those that will be seen when the disk drive is booted on the
NetWinder (/dev/hda in most cases). Also be sure to edit the right
etc/fstab file - you want to edit the one in the image you just
untarred, not the one belonging to the host PC.
The drive can then be unmounted and the PC can be powered down. The
NetWinder's hard disk should then be reinstalled. If the partition usage
has changed, then firmware settings may need to be changed. Consult section
2.5 for details, but remember to use the appropriate /dev/hdaX
value for your particular situation.
It's possible to update or reinstall a NetWinder disk image via a parallel-port device, such as the Backpack CD-ROM. Its pretty slow and therefore not recommended in general, but if you happen to have a suitable drive, and don't mind waiting, then this method is for you.
There are two variations on the parallel port method. One way is to use the parallel port device simply as a storage place for the diskimage tar file. In this case, the NetWinder must have enough room on a spare partition to hold the uncompressed disk image. You'll also need to make or obtain a CDROM (or tape or disk, as the case may be) containing the image tar file.
Alternatively, it is possible to boot off the parallel port device (at least, San made it work a long time ago). In this case, the NetWinder's hard disk could theoretically be reformatted and the new image installed over top. Therefore you would not need a "spare partition" to hold the new image. The difficulty with this method is that you need a bootable CDROM, and unfortunately I can't tell you how to make/obtain one. If anyone has experience, please let me know.
A partition should be freed up to make room for the uncompressed image.
The process is described in sections 2.2 and 4.3 (read both if in doubt).
It will be assumed in the following that /dev/hda3 has been freed
and is mounted on /mnt/hda3.
Next, the parallel port device needs to be made available. Ensure that it's plugged in and powered on. Most likely the device will be a CD-ROM player, since zip drives are not large enough to hold the disk image. So the example listed here will assume a Backpack CDROM. This happens to be a device that I have tested. For other parallel devices, consult http://netwinder.org/~ralphs/parport.html for the appropriate commands.
insmod nls
insmod isofs
insmod paride
insmod bpck
insmod pcd
mount -o ro /dev/pcd0 /mnt/cdrom
To verify that it's working right, issue the command ls /mnt/cdrom
and you should see the diskimage tarball in the listing.
As in the other install methods, the disk image should now be untarred to the free disk partition. The command sequence will be similar to
cd /mnt/hda3
tar zxpf /mnt/cdrom/YourImage.tar.gz
Naturally you have to substitute the appropriate name for
YourImage. The process could take quite a long time, since the
transfer over the parallel port is rather slow. It also uses a lot of CPU
power, so the computer may be very slow to respond if you try and do
anything else while the image is uncompressing.
Be sure to fixup the etc/fstab file in the newly installed image
before shutting down, and adjust the firmware parameters upon reboot.
Please refer to sections 2.4 and 2.5 for the details on how to do this.
This chapter describes how to restore a NetWinder disk using the `rescue' flash filesystem. This allows a NetWinder to boot completely from the flash memory, and then become an NFS server. You can then use a second computer on your network to connect to the NetWinder and install a new disk image.
Thanks go to Mike Montour (mmontour@iname.com) who first put together the
rescue filesystem and has been improving it ever since. San Mehat adapted
the filesystem so that it could be stored in flash memory. I've also
twiddled with it a bit and released my own version
(nettrom-2.0.4a+ralphs). Please note that the startnfs script
described below only exists in the 2.0.4a+ralphs version!
First and foremost, this method requires a NetWinder with a rescue filesystem embedded in the firmware. The only sure-fire way to find out is to try and boot the rescue filesystem (see section XX below). If your machine boots as usual off the hard disk, you don't have rescue firmware installed. In that case, either upgrade the flash (see the Firmware-HOWTO at http://netwinder.org/~ralphs/howto/Firmware-HOWTO.html), or use one of the other installation methods.
The second requirement is to have another computer, preferably a unix machine, which can act as an NFS client. The diskimage tarball should be downloaded to this machine. This machine will then mount the NetWinder's hard disk and untar across the network to the NetWinder.
As with the other methods, a partition should be freed on the NetWinder disk (unless you plan to reinstall everything, in which case you can just format the partition, of course). Consult sections 2.2 and 4.3 for more information on how to free a partition.
The NetWinder will now be turned into an NFS server and be made to export the (empty) partition so that it can be mounted from the `other' computer. The first step is to reboot the NetWinder and to enter the firmware menu by pressing a key when prompted, `Press any key to abort autoboot'. Configure the NetWinder's IP address and netmask, and enable the rescue filesystem:
setenv netconfig_eth0 flash
setenv eth0_ip 192.168.1.1/24
setenv rdconfig flash
boot
Be sure to specify the NetWinder's actual IP address and netmask. The welcome message should then be displayed. If you do not see it, or if the system boots off the hard disk like it usually would, then your firmware lacks a rescue filesystem. In this case, you can either change the firmware, or use one of the other installation methods.
Optionally, the mke2fs and e2fsck commands can now be used
to format and verify partitions, respectively. The partition table itself
cannot be altered, unfortunately, since there is not enough room in the
rescue filesystem for the fdisk program to be included.
The last step is to actually export the (empty) partition, and to start the
NFS daemons. Mike has set up a convenient script for doing this. For
reasons unknown, firmware versions with the rescue suffix don't
include this script (perhaps San didn't think it was needed...) There is a
corrected version called nettrom-2.0.4a+ralphs which does include
the script (and is otherwise identical). The following example shows how to
use the script.
startnfs 192.168.1.254 /dev/hda3
This causes /dev/hda3 to be mounted on /mnt/localdisk and
then exported to the host 192.168.1.254. You should of course substitute
the IP address of your `other' computer in its place.
If the startnfs command fails, try rebooting and repeating the
startnfs process again. Usually it succeeds after a few tries. If you have
repeated problems, you can contact me for help (mostly because I'd like to
nail down exactly what the conditions are that lead to the problem).
The other computer will now mount the NetWinder's exported filesystem. I
suggest creating a mountpoint /mnt/netwinder for this purpose.
Substitute the NetWinder's actual IP address into the following mount
command:
mkdir /mnt/netwinder
mount 192.168.1.1:/mnt/localdisk /mnt/netwinder
If this fails, try pinging the NetWinder to make sure the network connection
is working. If ping works, but the mount fails, go back to the
NetWinder and ensure that the NFS service started without errors. On some
systems, you might have to add the flag -t nfs to the mount
command.
To verify that things are working, try doing ls /mnt/netwinder.
This should show an empty filesystem. The df command should show
that /mnt/netwinder has sufficient space to hold the uncompressed disk image
(about 650 MB for build #12).
The image can be untarred directly to the NFS disk image now. Since the
uncompressed data must be transfered over the network, it could take quite
some time. Be patient... To monitor progress, you can switch to another
terminal and use the df command.
cd /mnt/netwinder
tar zxpf /path/to/YourImage.tar.gz
You will have to supply the full pathname for YourImage. The image
could of course be located on another NFS (or otherwise) mounted volume, if
you wanted to.
Be sure to fixup the etc/fstab file in the newly installed image
before shutting down, and adjust the firmware parameters upon reboot.
Please refer to sections 2.4 and 2.5 for the details on how to do this.
Note in the examples in section 2.x assume your new image to be located on
/dev/hda3; if you've used a different partition, you must adjust
the examples to suit.
This chapter describes how a NetWinder drive can be updated by NFS booting the system from a remote host. This is the most flexible way to update a NetWinder, and it is also (perhaps) the most tricky one to set up for novices.
This method requires a second computer which will act as the boot server for the NetWinder. This server must support NFS and TFTP services, and an ethernet connection of course. It must also have lots of disk space, enough to hold a compressed and an uncompressed version of the NetWinder disk image.
The NetWinder in this case needs 2.0 firmware or better, and everything else is negotiable. Since the NetWinder will boot from the server, you can safely format the NetWinder's hard disk and install a new diskimage onto it. Therefore you only need enough room to hold the uncompressed image (so it will even work for the 810 Meg drives).
The server needs to be configured so that it can provide a kernel via TFTP, and a root filesystem via NFS for the NetWinder. The examples that follow are written for a PC running RedHat Linux. Things should be pretty similar for most other unix-like operating systems, but I can't possibly list all the different systems.
It is possible to use a second NetWinder as the boot server. The only thing
to watch out for is that the tftp daemon that's shipped on all disk images
up to #14 suffers from an alignment bug, and therefore doesn't work. The
symptoms include an error message about "GAL tftp operation". The fix is
pretty simple: arpa/tftp.h must be fixed, then tftpd must be
rebuilt.
For simplicity, the following examples assume static IP addresses for both the NetWinder and the rescue server. It is possible to use DHCP, and if you plan on NFS booting many NetWinders, it is even a good idea. However, to improve your chances of actually getting this proceedure to work, the topic of DHCP is left out here.
/nwrootBegin by unpacking the NetWinder diskimage tarball on your server. Create a
directory called nwroot (or other name if you prefer) in the
filesystem root. If you don't have room to unpack the image there, you can
put the directory elsewhere and make a symbolic link.
mkdir /nwroot
cd /nwroot
tar zxpf /path/to/YourImage.tar.gz
The fstab file in the image must be updated to match the way this image will
be booted. Therefore, edit /nwroot/etc/fstab and comment out all
the lines that begin with /dev/hdaX. Then add a line as follows,
but replace the IP address with the server's actual IP address:
192.168.1.254:/nwroot / nfs defaults 0 0
Save the file and your /nwroot will be ready for action.
Notes for kernel 2.2.x and beyond: Upon booting you may encounter
the message `Unable to open initial console' if using the older
rescue packages or disk images. If this happens, the solution is to create
a /dev/console entry (major 5, minor 1) in your NFS image.
Alternatively, you can create a symbolic link from /dev/console to
/dev/tty0.
The nwroot directory now needs to be exported so that the NetWinder
can boot from it. I'll assume the NetWinder's IP address to be 192.168.1.1,
substitute your real address. On the server, edit (or create)
/etc/exports so it contains the following line:
/nwroot 192.168.1.1(rw,no_root_squash)
Restart the NFS service, so that the changes take effect. On RedHat systems, the command would be:
/etc/rc.d/init.d/nfs restart
If this causes trouble, ensure that you installed NFS server support in the
first place. Additional RPM's might need to be installed. For NFS server
support you need the programs portmap, rpc.mountd and
rpc.nfsd (and maybe others too..).
The server needs to support the TFTP protocol, since the NetWinder will try
to get a kernel using this method. Normally, a special directory would be
reserved for storing the files to be sent by TFTP. However it's simpler in
this case to use the boot directory in the NetWinder disk image,
since it already contains the kernels (no point in making additional
copies).
To enable the tftp service, it needs to be added to the
/etc/inetd.conf file. Most systems will already have an entry for
it, probably commented out though. In any case, make sure there is an
un-commmented line that reads:
tftp dgram udp wait root /usr/sbin/tcpd in.tftpd /nwroot/boot
Note in particular that the directory has been specified as the last argument. This means that when processing a tftp request for a file, the server will look in that directory. To effectuate the changes, the inetd process must be sent a SIGHUP. On a RedHat system this can be accomplished with the following command.
killall -HUP inetd
In principle, your server should now be ready.
The NetWinder will now be booted from the server. Turn on the NetWinder's power (or reboot it if it was running) and interrupt the boot process at the `Press any key to abort autoboot' prompt. Now the settings for diskless booting need to be adjusted in the firmware. The first thing to do is to assign an IP address and netmask for the NetWinder.
setenv netconfig_eth0 flash
setenv eth0_ip 192.168.1.1/24
Naturally you should put in the NetWinder's real IP address and netmask value. The next step is to configure the firmware so that it will fetch the kernel from the server, instead of reading it from the local hard disk:
setenv kernconfig tftp
setenv kerntftpserver 192.168.1.254
setenv kerntftpfile vmlinux
Substitute the server's IP address above. Finally, the firwmare is told to use the NFS exported directory as the root filesystem.
setenv rootconfig nfs
setenv rootpath 192.168.1.254:/nwroot
boot
If you wish, you can issue the save-all command before the boot
command - if something fails, you won't have to type all those setenv's
again. Later on, when the new disk image has been installed, you need only
change kernconfig and rootconfig to switch back to local
(disk-based) booting.
Diagnosing what is failing can be quite difficult sometimes. There are a large number of things to check, any of which could cause trouble. The following tips will hopefully help in diagnosing the problem. If you get really stuck, as for help on the mailing lists / newsgroups.
The first thing that should happen after the boot command is given
is that the kernel should be downloaded via TFTP from the server. A counter
will show the bytes as they are received, and it should take a couple of
seconds at least (the kernel is about 1MB in size). If the count doesn't
appear at all, there is a problem with tftp on your server, or a networking
problem (NetWinder can't talk to the server). Check the the IP addresses
and netmasks.
If downloading succeeds, the kernel will then be booted. If your monitor goes black or looses sync for an extended time, then the kernel failed to boot. Check that your firmware is compatible with the kernel that the TFTP server is sending. You might have to upgrade or downgrade one or the other.
The kernel should then boot, and print its usual messages about detected hardware. Then it will try to mount the NFS share. IF the mount fails, it might hang here, or give an error. If it says "NFS server not responding, still trying" then be patient, it will probably work. Anything else (error -13 for example) means the NFS export couldn't be mounted. Check the server, maybe try mounting it from yet another machine.
One of the first things you'll see after the NFS is successfully mounted is the message "INIT version... starting". In this case you should be home free. Expect some warnings during the nfs boot (for example, ef2sck will complain when it tries to scan the root disk, since it can't handle an nfs filesystem). You should eventually get to a login prompt.
Once the NetWinder is nfs booted, you should login in as root (password is
'vnc') and then type mount to ensure that you really are NFS
booted. The output from mount should show that "/" is not mounted on
/dev/hda1.
At this point there are a number of options. If you wish, you may
repartition the NetWinder's hard disk by typing fdisk /dev/hda. If
you do so, you'll have to format the new partition with mke2fs.
This will of course erase everything on the disk. (Please see the note in
section 2.2 regarding the -O sparse_super option).
In any event you should free up a partition to hold the new disk image. For
consistency with previous chapters, I'll assume that /dev/hda3 has
been freed in the following examples. See sections 2.2 and 4.3 for tips on
how to free a partition.
You can untarr the diskimage to the free partition, or you can copy recusively all the files from the NFS mount to the free partition. The former is quicker so I'll describe it here.
On the server, the YourFile.tar.gz diskimage should be copied or
moved into the /nwroot directory. It will therefore be visible to
the NetWinder.
On the NetWinder, the image can be installed using the following commands.
mount /dev/hda3 /mnt/hda3
cd /mnt/hda3
tar zxpf /YourImage.tar.gz
Since the files are being copied across the network, this process could take some time.
Be sure to fixup the etc/fstab file in the newly installed image
before shutting down, and adjust the firmware parameters upon reboot.
Please refer to sections 2.4 and 2.5 for the details on how to do this.
Note in the examples in section 2.x assume your new image to be located on
/dev/hda3; if you've used a different partition, you must adjust
the examples to suit.
If you used the save-all command in section 7.3 above, then
remember to "undo" those settings so that your machine will boot from its
hard disk again:
setenv kernconfig fs
setenv rootconfig disk
save-all
That's it!
This method was developed by Mike Montour (mmontour@iname.com) as an alternative to the full NFS-boot method described in the previous chapter. It's meant to simplify the process of configuring the server, and it also takes less space on the server (since it doesn't require the whole NetWinder disk image to be decompressed).
Mike has prepared a README for the use of his rescue filesystem. It is available at http://www.netwinder.org/~mmontour/. The NFS-rescue disk images are also available from the same place. Overall, the process is similar to that described in the previous chapter, `NFS booting'. Some of the differences include:
load-defaults
setnetwork eth1 (or eth0)
setenv kernconfig tftp
setenv rootconfig nfs
boot
(It should get everything else over DHCP)
/exports/hdaN by default.
Unpacking the tarball from the NFS host onto the local disk is also the
preferred installation method with my package (which now includes tar).
Notes for kernel 2.2.x and beyond: Upon booting you may encounter
the message `Unable to open initial console' if using the older
rescue packages or disk images. If this happens, the solution is to create
a /dev/console entry (major 5, minor 1) in your NFS image.
Alternatively, you can create a symbolic link from /dev/console to
/dev/tty0.
Here is a list of things to check when nothing is working. Unfortunately, it is not very complete listing. If you've got suggestions for things to add, please mailto:ralphs@netwinder.org.
etc/fstab
Be sure to check the etc/fstab file in your new disk image before
shutting down and trying to boot it for the first time. The default file
might not be applicable to the way you've partitioned your disk. Make sure
that there are entries for only those partitions you actually use. Comment
out any /dev/hdXY lines if you don't need them.
Also, make sure that the root device is properly specified. The root device
is the line whose mountpoint (second column) is simply `/'. Make sure that
the device name immediately to the left of it actually is the partition
where you've installed the disk image. This should be the same value that
you put into the rootdev parameter in the firmware.
etc/mtab
If there is a file called etc/mtab in your newly installed image,
delete it. This is used to cache the actual mounted filesystems (it looks
much like /etc/fstab). The system will re-create a proper file
when it needs one. Having an old version of mtab around can prevent the
machine from booting.
/proc, /mnt
Sometimes the mountpoints don't get included in a disk image. Fix this by going to the root directory of the new image and running the following commands.
mkdir proc
mkdir mnt
mkdir mnt/hda1
mkdir mnt/hda2
mkdir mnt/hda3
When booting a 2.2.x kernel on a disk image designed for 2.0, you may
encounter the message `Unable to open initial console' shortly
afteer the kernel boots. The solution is pretty simple, you have to create
a /dev/console entry in your NFS disk image. Either of the
following two command can be used; the first one is preferred:
mknod /dev/console c 5 1
ln -s tty0 /dev/console
Keep in mind you want to create the node in the NFS image that's exported to
your NetWinder for booting, as opposed to the root filesystem of your NFS
server. So you should really say /path_to_nfs/dev/console instead
of /dev/console.
If you're getting this error whey you try to boot your newly installed
system, then the problem is that you used a new version of mke2fs
and it has turned on some new features, which the NetWinder firmware does
not understand. Until the firmware is fixed, the solution is to use
mke2fs -O sparse_super /dev/hdaX when you format your filesystem.
It may also be possibly to change this after-the-fact with the tune2fs
program, but I've not tried it.
The author and maintainer of the NetWinder Disk-Update-HOWTO is Ralph Siemsen (ralphs@netwinder.org). Please send me any comments, additions, corrections so that the can be included in the next release. The latest version of this document can be obtained from http://www.netwinder.org/~ralphs/howto/Disk-Update-HOWTO.html.
The `sgml2info' version of this document doesn't show the examples properly - for some reason the linefeeds are removed. Why is this and how do I fix it?
May 22, 1999 (version 1.0): First public release of this document.
May 27, 1999 (version 1.1): Completed missing sections, added links to Carelton project, put in more cross-references.
Jun 7, 1999 (version 1.4): Added NFS-rescue section (thanks Mike!)
Jun 21, 1999 (version 1.5): Fixed typo in section 6.2 NetWinder setup (thanks to Steve Cockwell), added clarification about "rescue" versus "ralphs" versions of the firmware.
Dec 12, 1999 (version 1.6): Fixed typo in section 7.2, the filesystem type in the example was incorrectly listed.
Apr 10, 2000 (version 1.7): Documented the -O sparse_super option
for mke2fs, which is necessary on dm-3.1-15.
Right now this is a product entirely of my own imagination.
Mike Montour (mmontour@iname.com) designed the NFS-rescue package.
Steve Cockwell (stevec@sierra.lazarus.ca) spotted a typo in the Rescue-firmware chapter.
Jason Jackson (jrjackso@warg.uwaterloo.ca) spotted a typo in section 6, it
should read netconfig_eth0...
Sean MacLennan (seanm@netwinder.org) for spotting a typo in section 7.2, the
/etc/fstab entry should show a filesystem of nfs and not
ext2.
Robert Scwartz (roberts@corel.com) caught my silly typo of the
sparse_super option for mke2fs.
This document is copyright (c) Ralph Siemsen, 1999.
Permission is granted to make and distribute copies of this manual provided the copyright notice and this permission notice are preserved on all copies.
There is no warrantee whatsoever.