Downloading and Upgrading Ubuntu
In this section :-
Downloading
Ubuntu
Point your browser to one of
the official Download
pages above, check which version you want and a suitable download
mirror site.
If you're planning to install Ubuntu onto an old PC with
little
memory, the Alternate CD may be more suitable. For more on
this
see Getting
Ubuntu in Windows where this is discussed in more detail.
Using K3b to check the ISO, burn to
CD/DVD and verify written data
There is a
CD and DVD burning program that provides more features than the
in-built Nautilus writer. This is K3B and available
simply by using Add/Remove... from the Applications menu - Sound & Video group or Synaptic to find, download and install it.
Not only will it burn CDs and DVDs (and erase CD-RWs) but
will erase DVD+/-RWs (which Nautilus fails to do) and will verify
written data, and also provide an md5
sum for the chosen ISO file which may be compared with the
official md5 sum
for that particular version, to check the download. No command line required.
Using
K3b :-
- Insert recordable CD or DVD into
your burner drive (if you do this first K3b will detect the type of disc when it's run)
- Cancel the pop-up asking what to do
- Run
K3b from the
Sound & Video
menu
- The screen shows a file navigation section and options - choose the ISO file to burn and click on it.
- Another
window pops up and the Md5 Sum is calculated. This
may then be
compared with the official checksum in the UbuntuHashes
secure web page. Copy the appropriate hash from the web page, right-click on the checksum in K3b and paste into the compare box to automatically check the hash (checksum)
- Further down you can set Verify
and choose the burning speed
- When you're ready click Start to begin the
process
- If re-using a CD-RW or DVD +/- RW you will
be prompted to allow erase/format
the disc
- Then
the writing will begin followed by
verifying the data (if Verify set). The drive opens and closes
again between erasing and between writing and verifying. Do not
remove the disc until K3b shows Success (or an Error).
The CD or DVD is now available for use either on the same computer or a different one.
Next Runnng the Live CD
or Using the Alternate CD to install Ubuntu (yet to be written)
An alternative - Using the command line and Nautilus
Using command line to check
the integrity of the download
It
is recommended that before burning the image to CD, you check that the
download was error free. This will not only detect download
errors but
any tampering with the software. Ubuntu has a checksum
facility installed by default. The usage is md5sum <filename>
where <filename>
is the name of the file you've just downloaded.
eg.
to use it with the Live CD version of Ubuntu Hardy (8.04) for the
i386 (standard Windows PC), type this line into a terminal
window
:-
md5sum ubuntu-8.04-desktop-i386.iso
After processing
takes place you should get a result containing the checksum.
eg.
8895167a794c5d8dedcc312fc62f1f1f ubuntu-8.04-desktop-i386.iso
This
may then be
compared with the official checksum in the UbuntuHashes
secure web page.
For more info see HowToMD5SUM in
the Ubuntu Community documentation.
Burning
the ISO image onto CD
Ubuntu has a built-in CD
and DVD writing facility. After inserting a writeable CD (or
DVD) in the drive, just right-click
on the ISO
file and choose Write to
Disc. The Write
speed may be reduced to to improve reliability if this is
an issue with the writer drive. Click the Write button and the
ISO image will be written to the disc. This will take some
time.
Verifying the written disc data.
The
written data may be checked at this stage to confirm the data has been
correctly written. The md5sum
utility may again be used to do this but instead of a checksum for the
disc as a whole, each individual file is checked. A list of
md5 checksums is provided separately in a text file on the CD image for
this purpose - the calculated checksum (or hash) being compared with
the correct value in the text file.
First mount the
CD, if not already mounted. The example assumes the CD/DVD
drive you're using is hda
and mounted at /cdrom
- alter as required. -
sudo mount /dev/hda /cdrom
Then change to the CD mount directory and use the supplied
md5sum file on the CD
- cd /cdrom
md5sum -c md5sum.txt | grep
-v 'OK$'
If the command outputs any errors, you'll know
the data is corrupt.
There is also a disc check
provided when using the CD. However, if a different drive (or
a different PC) is used to run the CD and errors are detected you won't
know if the problem lies with the CD or the reading drive.
If the above check proves successful and reading in
the other drive shows errors then the fault is with the second drive.
Next Runnng the Live CD
or Using the Alternate CD to install Ubuntu (yet to be written)
Updated 6 May 2008