[arch-general] Upgrading while using a package (WAS: Re: pacman -Syu -- then tons of kio and kbuildsycoca warnings. Bug or coincidence?)

[diederick]

On Thu, 14 Oct 2010 09:09:27 +0200, Stefan Husmann
<stefan-husmann at t-online.de> wrote:
> Am 14.10.2010 08:40, schrieb diederick:
>> On 10/13/2010 11:03 PM, David Rosenstrauch wrote:
>>
>>> On 10/09/2010 12:57 AM, David C. Rankin wrote:
>>>> Guys, just updated and got a slew of warning dumped back to konsole:
>>
>>> Nothing strange to me at all:  you're upgrading qt while you're in KDE
>>> (which uses qt).  It's never a good idea to upgrade a package while it's
>>> being used.  If you're upgrading a daemon, shut down the daemon first;
>>> if you're upgrading qt, exit KDE first; if you're upgrading the kernel,
>>> udev, etc., drop to single user mode first.
>>
>> I didn't know that, nor did I read that somewhere on the wiki. Why is
>> this? Aren't programs copied to memory (i.e. loaded) before being used?
>> In that case, isn't the upgraded version left alone until it is loaded
>> the next time the program is started? Where can I find more on this?
>>
>> Thanks,
>> Diederick
>>
>> --
>> http://www.diederickdevries.net/
>>
>>
> 
> Hello,
> 
> in general you are right, but you never know. Programs are doing something. 
> Some may reload data files even or program code at runtime. 

Right. In your earlier post, you specifically mention the kernel. Would
you say that it is safe to install a new kernel in multi user mode if I
reboot right after installation, while not using modprobe et al. between
the installation and the reboot? And if not, why is single user mode
safer?

Thanks for your quick response,
Diederick

-- 
http://www.diederickdevries.net/