Sugar on a Stick/Linux

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Revision as of 13:08, 9 October 2012 by FGrose (talk | contribs) (--delete-home not needed with --format)
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Introduction

This page provides additional detail for loading Quandong, the most stable, released version of Sugar on a Stick (SoaS), available at Sugar on a Stick/Downloads, onto a USB/SD flash storage device using GNU/Linux.

To explore a variety of experimental options for putting a Sugar image on a USB or SD flash drive under GNU/Linux, see the following pages:
SoaS test builds | OLPC XO-1 | openSUSE | Trisquel | VirtualBox | VMware | non-compressed Fedora | Live USB: (all known portable Sugar distributions)

If you have questions, trouble, or feedback, please let us know on the discussion page. If you can improve these instructions, please edit the page and do so!

Load SoaS onto a stick using Fedora or Ubuntu

This is known to work in Fedora and Ubuntu.

First, download a SoaS .iso image from http://spins.fedoraproject.org/soas/#downloads, then return here.

  • Make sure you have the syslinux package installed on the operating system that you will use to prepare the Live USB image. It is recommended that you also have the isomd5sum package installed. The cryptsetup package is another option potentially used by the "livecd-iso-to-disk" installation script. (On Ubuntu, sudo apt-get install syslinux isomd5sum cryptsetup will install the packages. They are also available through the Synaptic Package Manager.)
(On Gentoo, one needs to uncomment 'SAMPLE FILE' in /etc/mtools/mtools.conf to make syslinux work.)
  • syslinux is needed to set up booting on the FAT file system of the USB disc or Live CD.
  • isomd5sum is needed for the recommended verification step, which checks that the .iso file is complete after its travels. If there is a problem with the .iso file, the script will exit and provide a failure message. The verification step can be bypassed by using the --noverify option.
  • cryptsetup is only needed for the option to provide password protection and encryption for the persistent /home/liveuser folder. It is not necessary if one applies the recommended --unencrypted-home option. The --unencrypted-home option is preferred because the reduced overhead improves robustness with the compressed SquashFS file system employed by the Live USB deployment.
  • Plug in a 2 GB or larger USB stick into your computer.
  • Mount the 'SoaS.iso' image to reach the onboard livecd-iso-to-disk installation script:
sudo mkdir /media/soas/
sudo mount /path/to/Fedora-17-x86_64-Live-SoaS.iso /media/soas/
(mount: warning: /media/soas/ seems to be mounted read-only.)
  • Change the working directory to the LiveOS folder on the SoaS.iso mount:
cd /media/soas/LiveOS
  • Execute ./livecd-iso-to-disk --help for usage details. (The file is already executable.)
  • Check the USB device node name on your system. In the example below, the scsi device is /dev/sdc and filesystem partition on that device is /dev/sdc1:
$ df -Th
Filesystem    Type    Size  Used Avail Use% Mounted on
rootfs      rootfs     20G   12G  7.5G  61% /
udev      devtmpfs    1.6G     0  1.6G   0% /dev
tmpfs        tmpfs    1.6G  904K  1.6G   1% /dev/shm
tmpfs        tmpfs    1.6G  788K  1.6G   1% /run
/dev/sda2     ext4     20G   12G  7.5G  61% /
tmpfs        tmpfs    1.6G     0  1.6G   0% /sys/fs/cgroup
tmpfs        tmpfs    1.6G     0  1.6G   0% /media
/dev/sda2     ext4     20G   12G  7.5G  61% /tmp
/dev/sda2     ext4     20G   12G  7.5G  61% /var/tmp
/dev/sda2     ext4     20G   12G  7.5G  61% /home
/dev/loop0 iso9660    509M  509M     0 100% /media/soas
/dev/sdc1     vfat    3.8G  4.0K  3.8G   1% /run/media/MyAccount/MyUSBdiscMountPoint

Another way to find out the USB device node name on your system is issuing the command 

   sudo fdisk -l

and looking in the output for the disk that corresponds to the USB device, e.g., a disk described with a stanza like 

   Disk /dev/sd?: 1939 MB, 1939865600 bytes
   150 heads, 42 sectors/track, 601 cylinders, total 3788800 sectors
   Units = sectors of 1 * 512 = 512 bytes
   Sector size (logical/physical): 512 bytes / 512 bytes
   I/O size (minimum/optimal): 512 bytes / 512 bytes
   Disk identifier: 0x000e14bf
   
   Device Boot      Start         End      Blocks   Id  System
   /dev/sd?1   *        2048     3784703     1891328    c  W95 FAT32 (LBA)

where ? in /dev/sd? is (usually) a letter of the alphabet.

If you have only one storage device with 2 GB of nominal capacity, it will be easy to recognize the USB device in the fdisk output by looking at which device has (about) 2 GB of capacity. In the example above, "Disk /dev/sd?" reports to be as large as 1939 MB, that is almost 2 GB.

If you have more than one disk with about 2 GB of capacity, consider moving to a situation where you'll have only one device with 2 GB of capacity, because this will help out a lot in recognizing the drive correctly.

  • Unmount the drive,
sudo umount /run/media/MyAccount/MyUSBdiscMountPoint
(The /run/media/MyAccount/ path is the new, Fedora 17 standard mount point. Other operating systems may use /media/MyMountPoint.)
  • Check the disk partition table for a device, such as /dev/sdc,
sudo fdisk -l /dev/sdc   <----that's a lowercase letter 'L' for the list option.
    You should see something like the following: 
    $ sudo fdisk -l /dev/sdc

Disk /dev/sdc: 4012 MB, 4012900352 bytes
124 heads, 62 sectors/track, 1019 cylinders, total 7837696 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x0000a9c7

   Device Boot      Start         End      Blocks   Id  System
/dev/sdc1   *          62     7834071     3917005    c  W95 FAT32 (LBA)

    The asterisk, * , under the Boot column indicates that the partition is bootable.

        If it is missing, then execute the commands here:
    1. parted /dev/sdc
    2. toggle 1 boot
    3. quit
  • Run livecd-iso-to-disk as the root user, making sure to pass the correct USB device node name and to set overlay and home size appropriately, depending on the target USB device storage capacity.
./livecd-iso-to-disk --reset-mbr --overlay-size-mb 500 --home-size-mb 900 --delete-home --unencrypted-home /path/to/downloaded.iso /dev/sd?1
If the command fails telling you that /dev/sd?1 does not exist, try using the command for /dev/sd? (the name of the device) and not for /dev/sd?1 (the name of the partition), like this:
./livecd-iso-to-disk --reset-mbr --overlay-size-mb 500 --home-size-mb 900 --delete-home --unencrypted-home /path/to/downloaded.iso /dev/sd?
If the command fails returning a complaint about the filesystem not being mounted, and you can afford to loose all data on the USB device, you can try reformatting the USB device filesystem:
  • mount the USB device (e.g., by unplugging and re-inserting it),
  • repeat the steps for learning its device name (there can be situations when the device name has changed!)
  • issue the command with the --format --msdos options, like this:
Warning.png
Warning
The command described here will ask for a confirmation and will destroy all pre-existing data on your USB device.
See also How to Damage a FLASH Storage Device for a discussion of why using the factory format is preferred.
./livecd-iso-to-disk --reset-mbr --format --msdos --overlay-size-mb 500 --home-size-mb 900 --unencrypted-home /path/to/downloaded.iso /dev/sd?
In the above examples, the /path/to/downloaded.iso may be substituted with /dev/loop0, as this is the loop device that the mount command chose.
35px-Activity-write.png
Note
Additional USB or SD devices may be loaded from a running Sugar on a Stick image that was loaded with the livecd-iso-to-disk script (but not those installed by other methods) by running this command in the Terminal Activity as a root user:
/run/initramfs/live/LiveOS/livecd-iso-to-disk --reset-mbr --overlay-size-mb 500 --home-size-mb 900 --delete-home --unencrypted-home /run/initramfs/livedev /dev/sd?1
The livecd-iso-to-disk installation method has other advantages over the liveusb-creator method by allowing the creation of a separate, persistent /home/liveuser folder with the --home-size-mb NNN option. This feature avoids consumption of the write-once persistent overlay for Activity storage (see LiveOS image) and allows one to update the OS image while keeping the user files (by running the script against your existing installation but leaving out the --home-size-mb NNN option).
  • The --delete-home option is used to avoid an error message while requesting both a new home (with --home-size-mb) and a persistent home (indirectly with --unencrypted-home). You wouldn't use the --delete-home option on an upgrade of the operation system only.
Depending on the size of your USB stick, you may have to decrease --overlay-size-mb and --home-size-mb values (for example, for a 2 GB stick, use 500 for the overlay and 900 for the home folder).
If you have sufficient capacity on your target device, and format it with an ext[234] filesystem to overcome the 2048-MB fat32 file size limit, you may avoid the SquashFS compression by including the --skipcompress option in the script command line.
  • Watch out for errors in the output of the script, the script seems to ignore them! (and say all is fine on the last line).

livecd-iso-to-disk transcript

[LiveOS]$ sudo ./livecd-iso-to-disk --reset-mbr --overlay-size-mb 500 --home-size-mb 900 --delete-home --unencrypted-home /media/SoaS/Fedora-17-x86_64-Live-SoaS.iso /dev/sdc1
Verifying image...
/media/SoaS/Fedora-17-x86_64-Live-SoaS.iso:   470134baa7e48085595243e53b55d41e
Fragment sums: 7de3e14f3d5aa991343fa35bdfe3a1db59d578db95a844a63d22de789de1
Fragment count: 20
Press [Esc] to abort check.
Checking: 100.0%

The media check is complete, the result is: PASS.

It is OK to use this media.
Copying live image to target device.
squashfs.img
   512344064 100%   43.04MB/s    0:00:11 (xfer#1, to-check=0/1)

sent 512406681 bytes  received 31 bytes  44557105.39 bytes/sec
total size is 512344064  speedup is 1.00
osmin.img
        8192 100%    0.00kB/s    0:00:00 (xfer#1, to-check=0/1)

sent 8265 bytes  received 31 bytes  16592.00 bytes/sec
total size is 8192  speedup is 0.99
Updating boot config file
Initializing persistent overlay file
500+0 records in
500+0 records out
524288000 bytes (524 MB) copied, 5.1728 s, 101 MB/s
Initializing persistent /home
900+0 records in
900+0 records out
943718400 bytes (944 MB) copied, 152.195 s, 6.2 MB/s
Formatting unencrypted /home
mke2fs 1.42.3 (14-May-2012)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
57600 inodes, 230400 blocks
11520 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=239075328
8 block groups
32768 blocks per group, 32768 fragments per group
7200 inodes per group
Superblock backups stored on blocks: 
	32768, 98304, 163840, 229376

Allocating group tables: done                            
Writing inode tables: done                            
Creating journal (4096 blocks): done
Writing superblocks and filesystem accounting information: done

tune2fs 1.42.3 (14-May-2012)
Setting maximal mount count to -1
Setting interval between checks to 0 seconds
Installing boot loader
Target device is now set up with a Live image!

What's next?

After you've created your stick, it's time to boot your stick and test it out. Please also report your observations.

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