On 04/14/2011 01:58 PM, Ralf Corsepius wrote:
On 04/14/2011 02:01 PM, Vaclav Mocek wrote:
> On 03/10/2011 05:08 PM, Michael Cronenworth wrote:
>> Kam Leo wrote:
>>> It probably has less to do with the boot process and more with disto
>>> upgrading; i.e. less likely that user files get clobbered if /usr is
>>> separate.
>> Nope. It has everything to do with booting. Some packages in /bin
>> depended on libs in /usr/lib{64} so calling the init script before /usr
>> is mounted would fail. There's a discussion about this in the devel list
>> if you search the history for it.
> I thought that programs in /bin and /sbin are not dynamically linked ....
Nope - That's an urban legend.
Actually that's not strictly true. Many* of the binaries in these paths on UNIX
System V R4 systems were statically linked - certainly su was and I think also
others.
I'm not sure whether the BSDs ever had this although I am sure someone does - at
some point around 5.2 FreeBSD grew the /rescue tree (man 8 rescue on a FreeBSD
box) which is intended to contain statically-linked binaries for system recovery
in the event that the dynamically linked executables in /bin and /sbin are
unusable. I think they still have this in current releases although I've not
installed a BSD box in a few years.
Programs below /bin and /sbin are supposed not to access anything
below
/usr (e.g. be dynamically linked to anything below /usr/lib), c.f.:
http://www.pathname.com/fhs/pub/fhs-2.3.html#BINESSENTIALUSERCOMMANDBINARIES
and
http://www.pathname.com/fhs/pub/fhs-2.3.html#SBINSYSTEMBINARIES
Post-dates many of these conventions by decades.
Regards,
Bryn.
* if not all; I wasn't there back then and don't have spare time right now to
trawl through the references for evidence.