Separate /usr partition

[Ralf Corsepius]

On 04/14/2011 03:10 PM, Bryn M. Reeves wrote:
> 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.
Correct. Historically many of them were statically linked.

Most of these statically linked binaries existed for historical reasons, 
due to technical limitations of the OS or because maintainers wanted to 
avoid moving libs to /lib.

>> 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.
On linux, static linkage of /bin and /sbin binaries had never been 
required. It's just that there had been times when dynamically linking 
them wasn't possible.

Ralf