On Friday 14 August 2009 14:12, someone identifying as *John Goche*
wrote in /comp.os.linux.setup:/
> I have been following an article from a magazine
> called computer active which presented an ubuntu
> installation and would like to ask a few questions
> pertaining to ubuntu.
Hmm... I'm not an Ubuntu user but okay...
> I would like to ask a few questions with regards
> to the installation of ubuntu linux as part of a
> dual boot system with windows vista.
>
> 1. On the "Prepare disk space" screen, are boot
> partitions at the beginning of the disk on longer
> required for dual booting as it was three or so
> years ago?
The only two possible reasons I can think of which would have
necessitated a "boot partition" - whatever you mean by that - to reside
at the beginning of the available diskspace are the following:
(1) An older BIOS which had limitations with regard to the amount of
diskspace it could read from, starting at the first cylinder. The
BIOS runs in the processor's real mode, which is the DOS-compatible
mode of operation on x86 processors (unless you have an EFI BIOS
or Linux BIOS, which run in protected mode).
Modern BIOS versions no longer have this limitation with regard to
the area of the disk they can read from.
(2) DOS and the DOS-based Windows versions - i.e. Windows 95/98/ME -
required that they were installed in an active primary partition
which started within the first 32 MB of the hard disk's available
space. NT-based Windows versions - i.e. Windows NT, Windows 2000,
Windows XP, Windows 2003 Server, Windows Vista, Windows 2008 Server,
Windows 7 and whatever comes after that - do not require this, but
they *do* require that there is a Windows-readable primary partition
present, and this partition must be marked "active" in the MBR's
partition table. The Windows partitioning tools should take care
of this, and the GNU/Linux partitioning tools won't touch that flag
unless you explicitly tell them to.
> 2. On the "Who are you?" screen, does ubuntu setup
> the entered account to have superuser or regular
> privileges?
Every user account created during the Ubuntu installation procedure is
an unprivileged user account. However, as other replying posters in
this thread have pointed out, the first (and only the first) user
account you create during this installation phase will beget /sudo/
privileges.
/sudo/ is a commandline utility that allows you to launch a process with
superuser privileges. It is normally set up to ask the user for the
user's own password, but it can be set up to ask for the root password
instead, or to not ask for a password at all (which is not
recommended). /sudo/ also makes use of a timer, so that if the user
with /sudo/ access makes use of /sudo/ twice within a given timeout, he
or she will not need to enter the password again the second time.
All of this is configurable via the file */etc/sudoers.* The file has
a /man/ page, which I recommend reading.
> Why doesn't the ubuntu installation ask for a root password? What
> happened to the good old famous "root" account on ubuntu linux?
The root account is still there, but it is by default set up without a
password in */etc/passwd* and */etc/shadow.* Please note that in a
UNIX system, "no password" does not equal "a blank password". If a
user account does not have a password assigned to it, it cannot be used
for login.
Ubuntu sets up the root account without a password so that it cannot be
logged into - and you should certainly never log in as root in a GUI
environment, because it's very tempting to do "normal everyday work"
while logged in like that and in the process jeopardize the system's
stability and security.
The root account should not be considered "a poweruser account" but
"strictly-maintenance account". In a UNIX system, *every* user is a
poweruser - because everyone can make use of one or multiple
commandline shells with hundreds if not thousands of powerful utilities
- and those who have /su/ and/or /sudo/ access are even more powerful
than the others due to the added availability of system administration
tasks. This is why not everyone should be granted /su/ and/or /sudo/
access.
> So now ubuntu users can be configured as "quasi-superusers" having all
> or almost all the same power as root but, for safety enforcement
> in order to deal with human errors, the password used to log in is
> again required when running a privileged operation?
The "password used to log in" - as you describe it - is the password of
your own user account, and /sudo/ uses the user's own password by
default - again, this can be changed; see higher up in this reply - so
as to prevent them from using the /sudo/ feature too lightly and thus
erroneously.
However, as I have mentioned higher up already and as other posters have
also pointed out, only the first user account created during the
installation of Ubuntu (or Kubuntu, Xubuntu or Edubuntu and whatever
other variant[1] they release) will have /sudo/ privileges. Any other
user account that needs /sudo/ access must be explicitly granted this
access afterwards by the user who installed the system (since he is the
only one who can do that).
_____
*[1]* Ubuntu is the main distribution, and in its desktop installation,
it makes use of Gnome as the desktop environment - presumably with
either Metacity or Compiz as a window manager, because Gnome does not
have a window manager of its own, unlike KDE. Ubuntu will by default
also only install GUI packages which support Gnome.
Kubuntu is basically Ubuntu with KDE as the desktop environment and will
by default only install GUI packages with support for KDE, which is
built upon the Qt libraries. It is however possible to install Gnome
packages as well in Kubuntu, just as it is possible to install KDE
packages in Ubuntu, but this requires that the base libraries for
respectively Gnome or KDE be installed as well. Since Kubuntu uses KDE
and KDE has its own /kwin/ window manager, it does not require an
external window manager such as MetaCity or Compiz, although KDE does
support using Compiz instead of /kwin./ The /kwin/ version in KDE 4.x
is however equiped with all the 3D functionality of Compiz, so there
isn't really any need to use Compiz instead.
Xubuntu is the Ubuntu distribution with XFCE 4 as its desktop
environment. XFCE has less features than KDE or Gnome but is much
lighter on the resources and therefore better suited for machines with
slower processors and/or less RAM.
Edubuntu is an Ubuntu distribution aimed at children, and specifically
for educational purposes, so it's not quite a "gaming" distribution.
> Is this how ubuntu gets rid of having to log in as root to perform
> privileged operations?
There is seldom ever a need to log in as root, given that the /su/
command, which allows one to temporarily become root, has already
existed in all kinds of UNIX systems for a long time - /sudo/ is a
little newer.
Although I myself do not use any of the Ubuntu variants, I normally set
up my systems to disallow all root logins both at the local console and
remotely, except for single-user maintenance mode (alias runlevel 1) -
which normally does not require that the root password is entered,
although on my systems it does - and for access to /su./ So on my
systems, the root account does have a password assigned to it, but all
direct root logins are forbidden.
> Or is there perhaps a root user and a window pops
> up like in vista asking you to type in the root
> password when an executable needs root privileges?
The way I understand it - mind you: despite anything I know about
Windows and of which I may speak in my posts, I do not use Windows
myself - Vista would be using the opposite of the /sudo/ principle,
i.e. every user account has administrator privileges by default which
are then lowered for most tasks of a normal everyday use, and when you
need to perform administrative tasks, it then "drops out of" the
lowered privileges. And if my information is correct, then Vista would
be using this kind of set-up because a lot of the Windows functionality
still requires being run with administrator privileges, and Microsoft
deemed this approach easier than implementing the Windows equivalent of
the SUID bit on UNIX.
But then again, this is Microsoft logic, and thus by definition
perverse.
> But where and when is the root user configured?
In Ubuntu and all its variants, the root user account does exist but
simply does not have a password assigned to it, making it unavailable
for login. The first user account created during the installation
phase is given /sudo/ privileges, which allows this user account to do
everything root can do, including setting up a password for the root
user so that it can be used for login. Even though it is quite
possible and very easy to do this, I do not recommend it. Just because
you can does not mean that you should.
GNU/Linux is a UNIX-style system, and UNIX isn't Windows. One should
therefore not want or expect it to be, either, because that would only
result in the user adopting all of the Windows logic and habits,
resulting in lots of security problems that were never there to begin
with. It's a UNIX system, so you must use it as one - it's the only
proper way anyway in this day and age of networked computers.
> 3. I remember the days when it was not possible to
> boot from a USB memory stick (using a file which
> is not called a USB install key). What year and
> month was this change introduced into the PC
> world and by who?
Documented trivia can be found by using a webbrowser and a search
engine, so do your own homework.
What you're asking about is
totally irrelevant anyway. All modern BIOS versions can boot off a USB
stick.
> 4. I don't recall the directories /media and
> /srv appearing in the Linux File Hierarchy
> Standard (FHS 2.0).
They are however present in the FHS 2.3 - note: the File Hierarchy
Standard is not GNU/Linux-specific but rather UNIX/POSIX-compliant.
> What is the reason for introducing these two directories and what
> purpose do they serve?
You are being deliberately lazy here, because the webpage for the File
Hierarchy Standard explains all of the rationale behind these two
directories into detail. But okay, I'll humor you... <grin>
*/srv* is a directory that is to be used for the files and directories
needed by services running on the system, e.g. webpages being served
via the Apache webserver, FTP repositories, shared projects storage, et
al. All of this used to be put under various subtrees of */var* but
*/srv* makes it possible to access this under a top-level directory
branch, and this in turn makes it possible to have */var* and */srv*
mounted with different mount options.
In practice and with regard to GNU/Linux however, most distributions
which create a */srv* directory during system installation will leave
it empty and will still have things like Apache and ProFTPd configured
to use the traditional storage locations under */var/www* and
*/var/ftp* by default, leaving it up to the user who installs the
system to decide what */srv* will be used for. A common use would be
to store your multimedia files there, which you want to have available
to all users on the system, or the files belonging to a common project
that more than one user is working on at the same time. Somewhat
related to this, you could also set it up as an NFS share.
*/media* is a directory which serves as the parent to several individual
mountpoints for removable storage media, i.e. USB sticks, CD-ROMs,
DVD-ROMs, memory cards, floppy disks, Iomega Zip, Jaz and Rev disks,
USB hard disks and possibly - depending on the usage - eSATA hard
disks. All of these mountpoints used to live under */mnt* in
GNU/Linux, but */mnt* has in traditional UNIX always been a temporary
mountpoint for systems maintenance, not a parent directory for
removable storage. Moving all of these individual mountpoints out of
*/mnt* makes it possible to use */mnt* as a maintenance mountpoint
again without temporarily having to disable the use of the removable
storage mountpoints for the duration of this maintenance.
> In particular shouldn't media devices show up under /mnt when they are
> mounted and shouldn't each user have their own media files in their
> directory under /home/suchusername and shouldn't shared files
> go under /user/share ?
As above: removable storage devices used to be mounted to subdirectories
under */mnt,* but these subdirectories are now to be found under the
*/media* parent directory. This has nothing to do with media files -
presuming you are talking of multimedia files such as audio and video
clips. If such multimedia files are to be shared across user accounts,
then they should be put under a publicly accessable directory such as
*/srv,* and if instead for whatever reason they must remain private to
a particular user then they should be placed under said user's home
directory.
*/usr/share* - as another poster has pointed out - has a totally
different purpose. Everything that goes under */usr* is considered to
be software needed for the normal multi-user operation of the UNIX
system - this as opposed to "single-user maintenance mode", also known
in GNU/Linux as "runlevel 1" or "runlevel S", in which only the root
user can use the system and all networking and multi-user features are
disabled.
> Thank you for your help and answers about ubuntu and the associated
> installation process.
We like helping out people where we can - this is why we are here - but
a lof of the information you are asking about can be easily retrieved
by doing a little homework of your own. You are using a search engine
in order to post to Usenet newsgroups, so you might as well learn how
to use that search engine in order to find the information you are
looking for; that's what it was designed for... <grin>
--
*Aragorn*
(registered GNU/Linux user #223157)
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