[H-GEN] altering disk partitions

[Greg Black]

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alex_del at bigpond.net.au wrote [extensively re-formatted]:

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> From: Greg Black <gjb at gbch.net>
> > Mark Suter wrote:
> > 
> > > Yes.  Here's the "df -h" from my current home system:
> > > 
> > >     Filesystem            Size  Used Avail Use% Mounted on
> > >     /dev/md0               11G  5.0G  5.1G  50% /
> > >     /dev/md1               64G   18G   47G  28% /home
> > 
> > As far as I can tell, from quick reading of the messages in this
> > thread, everybody has given a different and quite correct
> > answer.  This is, after all, one of the great examples of Unix
> > flexibility -- and we are all in different situations with
> > slightly different needs.
> > 
> > Here's the df -h on the box I'm using right now:
> > 
> >    Filesystem    Size   Used  Avail Capacity  Mounted on
> >    /dev/ad0s1a    93M    32M    53M    38%    /
> >    /dev/ad0s1g   2.3G   1.1G   1.1G    50%    /usr
> >    /dev/ad0s1e   496M    39M   417M     9%    /var
> >    /dev/ad0s1f   496M    63M   394M    14%    /tmp
> >    /dev/ad2s1e    36G   8.3G    25G    25%    /org
> 
> IDE drives are labelled hda, hdb etc. SCSI devices and CD drives use 
> sda etc. What is md0? what is ad0s?

The naming of devices is dependent on the conventions of the
operating system (and, sometimes, the version) in use.  For any
system, you can find out what things are by using the man(1)
command.  For instance, "man ad" on the system with /dev/ad0s1a
would tell you all you need to know.

Historically, for many systems, PC hard disks were often called
"wd" (for the Western Digital controller that was popular when
Noah was a boy); then "sd" came to be used for SCSI disks; then
some of the BSD systems dropped "wd" in favour of "ad" and "sd"
became "da" for reasons that are too involved to cover here.

In my example above, "ad0" and "ad2" are two IDE disks, both
installed as masters on different channels; if "ad2" had been
jumpered as a slave, it would have been called "ad1" in this
setup.  The "s1" refers to the 1st (and in this case only) fdisk
partition on the disk.  Other fdisk partitions would have been
given "s2", "s3", etc.  And the "a" at the end "ad0s1a" means
the first Unix partition on that fdisk partition (or slice, as
it's known in this environment).

Here's the df -h output from my laptop:

    Filesystem    Size   Used  Avail Capacity  Mounted on
    /dev/ad0s2a    93M    36M    49M    42%    /
    /dev/ad0s2e   2.9G   1.3G   1.4G    48%    /usr
    /dev/ad0s2f   496M    16M   441M     4%    /var
    /dev/ad0s2g   496M   143M   314M    31%    /tmp
    /dev/ad0s2h   8.9G   5.0G   3.2G    61%    /org
    /dev/ad0s3a   2.8G   1.6G   975M    63%    /exp
    /dev/ad0s1    1.8G   889M   912M    49%    /c

It has Win-ME on the 1st slice (mounted as /c); then it has
FreeBSD-4.3 on the 2nd slice (ad0s2x); and it has FreeBSD-5.x on
the third slice (mounted as /exp[erimental]).

So, there's no one answer to this -- even though many Linux
users seem to assume that what they see on their Linux boxes is
the whole story.

Greg

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