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OpenSolaris and Linux on One USB Stick for Dual Usage

Bernd Schemmer, May 2008

Contents:

• 1. Introduction
• 2 Chosen Environment
• 3. Implementation Instructions
  • 3.1 Creating the Partitions on the USB Stick
  • 3.2 Installing Linux (DSL) on the USB Stick
  • 3.3 Installing OpenSolaris on the USB Stick
    • 3.3.1 Become Root User
    • 3.3.2 Create the Slices on the OpenSolaris Partition
    • 3.3.3 Create the File System on the Slice for Data
    • 3.3.4 Install MilaX
    • 3.3.5 Customize the GRUB Menu
    • 3.3.6 Customize the MilaX Ramdisk
  • 3.4 Finishing
• 4. Appendix
  • 4.1 The Final GRUB Menu on the USB Stick
  • 4.2. Invocation Syntax for Booting the USB Stick in a QEMU Virtual Machine
    • 4.2.1. General Hints
    • 4.2.2 Booting the USB Stick From Within Linux
    • 4.2.3 Booting the USB Stick From Within Microsoft Windows
  • 4.3 References

1. Introduction

My goal is to create a USB stick for rescue tasks in Linux and in the OpenSolaris Operating System for x86 platforms. Therefore, there must be a bootable OpenSolaris OS and a bootable Linux OS on the USB stick. In addition, because I do not want to reboot my PC every time for adding or changing something on the USB stick, the USB stick must also boot in a virtual PC environment. The virtual PC environment should be available on various operating systems. And the USB stick should also be usable in Microsoft Windows environments to save files on the stick.

All components used must be open source or at least freeware.

2 Chosen Environment

After some tests, I haven chosen the following components to implement this solution:

• A 2-GB USB stick from the BigAdmin Bucks Program, but this information should work with other USB sticks also ...!

• Linux Live CD-ROM DSL (Damn Small Linux) version 4.2.5 for the Linux portion:

  DSL is chosen because it's complete, fast, and very small (the ISO image needs only about 50 MB; see the DSL homepage).

• MilaX (OpenSolaris Small Live CD, version 0.3) for the OpenSolaris portion:

  MilaX is chosen because it's complete, fast, and very small (the ISO image needs only about 100 MB; see the MilaX homepage).

Note: MilaX is based on OpenSolaris build 81.

• The virtual machine emulator QEMU version 0.9.1 for the virtual PC environment:

  QEMU is chosen because it's fast, small, and available for various operating systems (OpenSolaris, Linux, Microsoft Windows, and so on). QEMU does not need a driver or something like this to run; the binary runs without an installation. And, most important, QEMU supports using real disk devices (disks, CD-ROMs, USB sticks, and so on) in the virtual machines.

  QEMU supports an accelerator to improve the performance, but the accelerator is not mandatory. On current CPUs with 2 GHz or more, QEMU runs fast enough even without the accelerator (see the QEMU homepage).

3. Implementation Instructions

3.1 Creating the Partitions on the USB stick

To have more than one OS on the USB stick and also an additional FAT partition for Microsoft Windows usage, the USB stick must be partitioned.

Notes:

• The following output is from within Linux, but the partitioning can also be done in OpenSolaris.
• /dev/sdb is the USB stick in the example. The device name for the USB stick depends on the machine configuration. Therefore, you should check the device name before continuing!
• You must use umount to unmount all partitions from the USB stick before creating a new partition table on the USB stick.

The first partition is a FAT-formated partition for the myDSL extension of DSL, the Microsoft Windows data, and the QEMU binaries. The second partition is for Linux boot (DSL), and the third partition is for OpenSolaris boot (MilaX).

3.2 Installing Linux (DSL) on the USB Stick

To install DSL on the USB stick, either boot the PC from the DSL Live CD-ROM and attach the USB stick or use QEMU for this purpose. The example below uses QEMU to install DSL on the USB stick.

Notes:

• You need the ISO image called dsl-4.2.5.iso for this task (where 4.2.5 is the version of DSL). It will not work with the other DSL ISO images for the version 4.2.5 (like dsl-4.2.5-initrd.iso, dsl-4.2.5-syslinux.iso, etc). But it will work with other versions of the DSL ISO image (like dsl-4.3.iso).
• The DSL installation on the USB stick from within QEMU should be done under Linux, because the QEMU version necessary for this task is 0.9.1 or newer.
• /dev/sdb is the USB stick in the example.

### start the DSL ISO image in a QEMU virtual machine
#
root@tp61p:/# /usr/local/bin/qemu -net user -usb \
  -usbdevice tablet -L /usr/local/share/qemu -m 512 \
  -net nic -redir tcp:1135::22 -name \
  "DSL_ISO_image_(user_network)_(ssh_port:_1135)" \
  -drive file=/dev/sdb,if=scsi,index=1 \
  -cdrom /data/nobackup/iso/dsl-4.2.5.iso  -boot d

Notes:

• The special parameter -drive file=/dev/sdb,if=scsi,index=1 is necessary for this invocation!
• To use an SSH session to connect to the virtual machine, you must enable the ssh daemon in the virtual machine and set a password for the user dsl.
• Do not use the DSL menu entry DSL/Apps/Tools/USB-HDD Pendrive Install to install DSL on the USB stick (because the script used there repartitions the USB stick).

The DSL script to install DSL on a USB stick repartitions the USB stick. Therefore, we must change that script before we can use it:

### create a writable copy of the script
#
root@box:~# cp /usr/sbin/pendrive_usbhdd.sh /tmp/

### edit the writable copy
#
root@box:~# vi /tmp/pendrive_usbhdd.sh

Search the function partition() and add return 0 as first line of the function, so that it looks like this:

partition(){
return 0

/sbin/sfdisk /dev/sda << EOF
.....

Next search for the line dd if=/dev/zero of=/dev/sda bs=512 count=1 and comment it out:

# dd if=/dev/zero of=/dev/sda bs=512 count=1

Now you can execute the corrected script to install DSL on the USB stick:

The DSL partition on the USB stick works in a QEMU virtual machine without changes, so there is nothing more to do here.

It's recommended to check the USB stick now. It should boot DSL on bare metal and in a QEMU virtual machine.

To boot the USB stick in a QEMU virtual machine use this:

root@tp61p:/# /usr/local/bin/qemu -net user -usb \
   -usbdevice tablet -L /usr/local/share/qemu -m 512 \
   -net nic -redir tcp:1135::22 -name \
   "DSL_on_USBstick_(user_network)_(ssh_port:_1135)" \
   -hda /dev/sdb  -boot c

3.3 Installing OpenSolaris on the USB Stick

Download the MilaX USB image from the MilaX homepage, and save it in a location that is also accessible after booting from the MilaX Live CD-ROM.

The usbcopy script from the MilaX homepage for installing MilaX on a USB stick is not usable for this purpose, because the script always creates one big slice on the OpenSolaris partition. Therefore, we will install MilaX manually on the USB stick.

To install MilaX on the USB stick, boot from the MilaX CD-ROM and attach the USB stick to the PC.

I recommend starting the X server after MilaX is up and running:

(alex@milax) ~ # startx

3.3.1 Become Root User

The first thing to do here is to become root user:

(alex@milax)$ su -
Password:
Sun Microsystems Inc.  SunOS 5.11  MilaX_03  April 2008
(alex@milax)#

Note: Be aware that the prompt does not change after switching to the root user! In this example, I changed the prompt manually to reflect the user ID.

Caution: The device name for the USB stick depends on the configuration of the machine used. Therefore, you should check the device name for the USB stick by using rmformat, for example:

(alex@milax)$ rmformat
Looking for devices...
  1. Logical Node: /dev/rdsk/c4t0d0p0
     Physical Node: /pci@0,0/pci-ide@1f,1/ide@0/sd@0,0
     Connected Device: HL-DT-ST DVDRAM GSA-U10N  1.05
     Device Type: CD Reader
     Bus: IDE
     Size: 107.0 MB
     Label: <None>
     Access permissions: Medium is not write protected.
  2. Logical Node: /dev/rdsk/c3t0d0p0
     Physical Node: /pci@0,0/pci17aa,20ab@1d,7/storage@2/disk@0,0
     Connected Device: Ut163    USB2FlashStorage 0.00
     Device Type: Removable
     Bus: USB
     Size: 2.0 GB
     Label: <None>
     Access permissions: Medium is not write protected

In the following examples, c3t0d0 is the USB stick.

3.3.2 Create the Slices on the OpenSolaris Partition

There will be three slices on the OpenSolaris partition:

The first slice, c3t0d0s0, is used for MilaX. The second slice, c3t0d0s1, is reserved for MilaX ZFS Boot, and the last slice, c3t0d0s3, is used for data.

3.3.3 Create the File System on the Slice for Data

The next step is to create a file system on the slice for the data:

(root@milax)# newfs /dev/rdsk/c3t0d0s3
newfs: construct a new file system /dev/rdsk/c3t0d0s3: (y/n)? y
/dev/rdsk/c3t0d0s3:	1093632 sectors in 178 cylinders of 48 tracks,
 128 sectors 534.0MB in 14 cyl groups (13 c/g, 39.00MB/g, 18624 i/g)
super-block backups (for fsck -F ufs -o b=#) at:
 32, 80032, 160032, 240032, 320032, 400032, 480032, 560032, 640032,
 720032, 800032, 880032, 960032, 1040032

3.3.4 Install MilaX

Next we copy the MilaX USB image to slice 0 of the OpenSolaris partition.

Now get access to the MilaX USB image; in my tests, I copied the image to a partition on my hard disk, which I then mounted from within MilaX.

3.3.5 Customize the GRUB Menu

The next step is the customization of the GNU GRand Unified Bootloader (GRUB) menu.

You should remove the string $ISADIR from all GRUB menu entries, if it exists. $ISADIR is only necessary for booting a 64-bit kernel if the hardware supports 64 bits. But there is no 64-bit kernel in the MilaX image, so the $ISADIR string should be removed. Note that this step is optional for machines with a 32-bit CPU, but it is mandatory for booting the USB stick on a machine with a 64-bit CPU.

Next, add the entry for DSL to the end of the GRUB menu:

3.3.6 Customize the MilaX Ramdisk

Now we must customize the MilaX ramdisk on the USB stick. To do this, first uncompress and mount the MilaX ramdisk.

/mnt/solaris0 is a partition on the internal hard disk in this example; it can be any file system with enough free space for the uncompressed ramdisk.

First, we configure the keyboard layout; this is done by editing the file bootenv.rc on the USB stick:

(root@milax)# vi /mnt/milax_ramdisk/boot/solaris/bootenv.rc

Change the string unknown in the line setprop keyboard-layout Unknown to the appropriate value; for example, for German keyboards, it should look like this:

setprop keyboard-layout "German"

Use the program kbd to get a list of the known keyboard layouts:

(root@milax)# kbd -s
USB keyboard
 1. Albanian                      22. Latvian
 2. Belarusian                    23. Macedonian
 3. Belgian                       24. Malta_UK
 4. Bulgarian                     25. Malta_US
 5. Croatian                      26. Norwegian
 6. Czech                         27. Polish
 7. Danish                        28. Portuguese
 8. Dutch                         29. Russian
 9. Finnish                       30. Serbia-And-Montenegro
10. French                        31. Slovenian
11. French-Canadian               32. Slovakian
12. Hungarian                     33. Spanish
13. German                        34. Swedish
14. Greek                         35. Swiss-French
15. Icelandic                     36. Swiss-German
16. Italian                       37. Taiwanese
17. Japanese-type6                38. TurkishQ
18. Japanese                      39. TurkishF
19. Korean                        40. UK-English
20. Latin-American                41. US-English
21. Lithuanian
To select the keyboard layout, enter a number [default 41]:

You can also change setprop atapi-cd-dma-enabled 1 to setprop atapi-cd-dma-enabled 0 now if the primary usage for the image is a QEMU virtual machine.

Now you can save and close the file.

The next change is in the init script, which sets the keyboard layout so that it honors the eeprom variable:

(root@milax)# vi /mnt/milax_ramdisk/lib/svc/method/live-fs-root

Replace the line kdb -s with this:

CUR_KEYBOARD_LAYOUT=`eeprom keyboard-layout | cut -f 2 -d "=" `
if [ "${CUR_KEYBOARD_LAYOUT}"x = "unknown" ] ; then
	kbd -s
else
	kbd -s "${CUR_KEYBOARD_LAYOUT}"
fi

The next change in the file live-fs-root allows booting the USB image in QEMU.

Search for the line volumeid=`cat /.volumeid` and insert the following lines after that line:

QEMU_DISK_RAW="/devices/pci@0,0/pci-ide@1,1/ide@0/cmdk@0,0:a,raw"
QEMU_DISK_BLOCK="/devices/pci@0,0/pci-ide@1,1/ide@0/cmdk@0,0:a"

Now replace the line lcmd="/sbin/listusb" with the following:

lcmd="eval /sbin/listusb ; echo ${QEMU_DISK_BLOCK} ${QEMU_DISK_RAW} "

Now you can save and close the file.

Make sure there is no syntax error in the file now (the warnings can be ignored):

The next change is necessary to correct the rights of the files in the user home directories.

Edit the file /mnt/milax_ramdisk/lib/svc/method/live-sysidtool-system:

(root@milax)# vi \
/mnt/milax_ramdisk/lib/svc/method/live-sysidtool-system

Search for the line find . -print | cpio -pmud /root and insert the following line after that line:

chown -R root /root

Search for the line find . -print | cpio -pmud /alex and insert the following line after that line:

chown -R root /alex

Now you can save and close the file.

The next change is necessary to get a correct prompt for the root user:

(root@milax)# vi /mnt/milax_ramdisk/etc/skel/.bashrc

Search for who am I. Replace the line u=`who am i | cut -f1 -d" "` with the following:

if [ `id -u` = 0 ] ; then
	u="root"
else
	u=`who am i | cut -f1 -d" "`
fi

I personally like to have the working directory in the prompt. Therefore, I change the prompt in the .bashrc file to this:

You can also add some code here to set the correct keyboard layout for X server settings. To do that, add the following lines at the end of the file .bashrc:

Change the value of the variable NEW_KB_LAYOUT in the previous code to the appropriate keyboard layout.

Save the file and exit the editor.

Check the file .bashrc for syntax errors:

(root@milax)# bash -x -n /mnt/milax_ramdisk/etc/skel/.bashrc

The last step is to copy some more utilities, which are useful if the mount of /usr fails, to the ramdisk:

(root@milax)# cp /usr/bin/cat /mnt/milax_ramdisk/usr/bin/
(root@milax)# cp /usr/bin/tail /mnt/milax_ramdisk/usr/bin/
(root@milax)# cp /usr/bin/less /mnt/milax_ramdisk/usr/bin/
(root@milax)# cp /usr/bin/svc /mnt/milax_ramdisk/usr/bin/
(root@milax)# cp /usr/sbin/svcadm /mnt/milax_ramdisk/usr/sbin/
(root@milax)# cp /usr/bin/svcs  /mnt/milax_ramdisk/usr/bin

Now unmount the ramdisk image, compress it again, and copy it back to the USB stick:

And umount the USB stick:

(root@milax)# umount /mnt/usb

3.4 Finishing

That's it. Now the USB stick is ready to use. The only things missing are the binaries for QEMU.

I leave it as an exercise for the reader to copy the QEMU binaries for Linux, Microsoft Windows, and OpenSolaris to the FAT partition of the USB stick.

4. Appendix

4.1 The Final Grub Menu on the USB Stick

Here is the final GRUB menu on the USB stick:

4.2. Invocation Syntax for Booting the USB Stick in a QEMU Virtual Machine

4.2.1. General Hints

The default network adapter emulated by QEMU is not supported by MilaX. Therefore, you must always specify the network adapter type if you are using QEMU to boot MilaX:

-net nic,model=rtl8139

The QEMU parameter -redir tcp:1135:22 enables SSH connections from the host running QEMU to the QEMU virtual machine (see the QEMU documentation for details). To connect using SSH to the virtual machine, use the following:

xtrnaw7@tp61p:~$ ssh -l alex -p 1135 localhost

Note: 1135 can be any free port above 1024 but it must be the port used for the parameter -redir tcp:1135::22 while calling QEMU.

4.2.2 Booting the USB Stick From Within Linux

Here's a script for booting the USB stick from within Linux:

4.2.3 Booting the USB Stick From Within Microsoft Windows

Here's a script for booting the USB stick from within Microsoft Windows:

Notes:

• The number in the parameter \\\\.\\physicaldrive1 depends on the hardware configuration of the PC.
• This syntax is known to work in Microsoft Windows XP and Microsoft Windows 2000. Some users say it does not work in Microsoft Vista. (I do not have Microsoft Vista running to check this.)

4.3 References

• MilaX homepage
• MilaX download page
• MilaX forum at OpenSolaris.org
• Damn Small Linux homepage
• Damn Small Linux download page
• Damn Small Linux forum
• QEMU homepage
• QEMU for Microsoft Windows binary download
• QEMU forum
• OpenSolaris QEMU project

Unless otherwise licensed, code in all technical manuals herein (including articles, FAQs, samples) is provided under this License.