[plug] Systemd, good or bad
Onno Benschop
onno at itmaze.com.au
Mon Sep 22 09:59:53 UTC 2014
It's taken me a little while to get my head around this, but boot time is
important in an environment where the uptime of a machine can be measured
in minutes. I hear you shaking your head, linux uptime in *minutes* - what
is he smoking and where do I get some? Bear with me.
In an AWS EC2 environment (or any other virtualised one) you might spin up
a machine to do some analysis of a logfile. When the processing is done,
you kill the machine and only rebuild and fire up the machine a week later
when you need to do some more processing.
Or you might spin up 100 machines to deal with a chunky load, then kill
them all, leaving 2 running, then spin up 40, kill 30, spin up 150, etc.
This is not how we have grown up to run our computers, but computing on
demand has made it possible to run a virtual machine at fast enough speeds
that the speed trade-off in using bare-metal is far outweighed by the
simplicity of management in spinning up just enough machines to do the job,
then killing them off when they're no longer needed. It's often cheaper to
spin up 100 tiny machines than it is to keep 2 big ones running all the
time. Amazon has pretty pictures to show this, but it's about reducing the
waste associated with "spare capacity".
This is happening at a massive scale across the globe, in virtual data
centres everywhere. Shaving off a couple of seconds for each machine is a
*big deal*.
This requires a different mind-set. Of course, the machine isn't often
customised to a particular task, it's a run-of-the-mill linux box that
stores its state outside the machine - using some configuration magic, or a
database, or some or other context sensitive thing. You might build your
own machine image, only with the bits you need, but making it fast is
important when you're running lots of little machines doing lots of little
tasks.
One of the ways that linux is pissing all over Windows in this environment
is that linux boots in seconds, where Windows boots in minutes. (And I'm
talking about servers, not desktops.)
So, that's why boot time is important.
Of course, if you implement something as far reaching as systemd, then it
pays to have the same tools across all your machines, be they dedicated
bare-metal machines, or virtual throw-away ones.
Do you need an amazing boot time for a machine that stays up for years - of
course not - and that's not what it's for.
Hope that this sheds some light on the subject.
o
On 22 September 2014 15:17, Brad Campbell <brad at fnarfbargle.com> wrote:
> Ok, I've really struggled with this one but it occurs to me that some
> people use vendor kernels and reboot when the vendor issues an update.
>
> I still don't understand _why_ boot time matters because by the time I've
> issued the reboot command I've moved on with my life before the thing has
> terminated the ssh session.
>
> Can you give me a concrete example as to why boot time matters?
>
>
> On 22/09/14 11:38, Hani Jabr wrote:
>
>> Boot times may not matter to most people who only use Linux desktops, but
>> when you have dozens or hundreds of servers boot times start to matter a
>> lot. Firmware upgrades, patches, app upgrades, system changes. You can
>> leave them up and running for years, but you don't. And that matters when
>> there's more than one.
>>
>> And let's face it, it's embarrassing for Linux when a sparc box takes
>> five times longer to POST and still boots up first...
>>
>> Hani
>>
>>
>>
>> On 22 Sep 2014, at 11:12, Brad Campbell <brad at fnarfbargle.com> wrote:
>>>
>>> I've heard a few people tout faster boot times as the main positive
>>> thing about systemd. Personally the 3-4 times a year I actually boot a
>>> linux machine makes me care a _lot_ less about boot times and a lot more
>>> about being able to fix broken stuff with basic hand tools.
>>>
>>> What I do care about is the ability to bring up and repair a broken
>>> machine without remote hands or worrying about the behavior of a dark bag
>>> of vipers. I can fix and/or tailor init scripts on the fly. I don't
>>> natively speak dbus.
>>>
>>> Hibernate/Suspend has worked well now for years. Even my laptop only
>>> gets cold booted a couple of times a year. If I need to boot into Windows I
>>> suspend Linux and pop the battery out. Boot Windows, and when I re-boot
>>> back into linux it just un-hibernates to where I was before.
>>> I suspend2both so if the battery dies I can un-hibernate, otherwise just
>>> wake it up with a keypress and I'm back in.
>>>
>>> I guess I'm just grumpy as I see it as yet another case of change for
>>> change's sake. Reading Lennart's blog again it really reads like he thinks
>>> linux will take OSX users by booting as fast as OSX, when in reality it's
>>> the totalitarian stewardship of OSX and the "one true path" that keeps
>>> users. They don't have to worry about dpkg vs rpm or Gnome vs anything else
>>> usable these days. It just works for a majority of the population and linux
>>> will never get there.
>>>
>>> When my mum phones up and asks a question about her Mac I can pretty
>>> much talk her through from memory, but when she uses the Ubuntu laptop I
>>> have set up for her to do her banking on I have to vnc in because shit
>>> keeps moving from release to release and I don't use Ubuntu anymore (and I
>>> can't see her coping with Debian and XMonad somehow).
>>>
>>> I see systemd as one of those black boxes that "just works", except that
>>> when it doesn't you are looking for a black button illuminated by a black
>>> light on a black control panel on a black wall in a black cave and it's
>>> very likely you'll be eaten by the Grue before you find it.
>>>
>>> Don't mind me, I'm just getting old and cantankerous.
>>>
>>> On 22/09/14 05:39, B15HOP wrote:
>>>> As much as I want to care about SystemD, I find that it's incredibly
>>>> fast with bootup times.
>>>>
>>>> Some people say that it's a turn for the worse, I think it's another
>>>> good option for another good cause. I think that Linux should always be
>>>> about modularity and user demand. If a person wants oranges instead of
>>>> apples, then so be it... Why do distro managers always try to make it
>>>> easier by just going down either A or B. It just cuts people out that
>>>> might already enjoy the distro. There are so many distros out there that
>>>> Linux has become obfuscated rather than a collaboration effort. Linus
>>>> then wonders why it hasn't won over the desktop, pretty easy to see
>>>> why... As much as I don't like SystemD, it grew on me once I got the
>>>> hang of it.
>>>>
>>>> A happy Arch user.
>>>>
>>>> Phillip.
>>>>
>>>> On Mon, Sep 8, 2014 at 6:56 AM, Bill Kenworthy <billk at iinet.net.au
>>>> <mailto:billk at iinet.net.au>> wrote:
>>>>
>>>> Systemd caused one of the longest ever flamefests on the gentoo mail
>>>> lists! - end result is openrc is still the default init but we have
>>>> to
>>>> put up with odd bits of systemd and its servants scattered through
>>>> the
>>>> system :( Systemd had a (very) few supporters but its more that its
>>>> being forced on people against their better judgement.
>>>>
>>>> The reputation of the systemd devs is very poor due to pulseaudio so
>>>> that is a black mark against it being just "accepted" - the battle
>>>> lines
>>>> have already been drawn - it will be interesting to see if redhats
>>>> data
>>>> centre business suffers irreparable damage as the resistance from
>>>> server
>>>> admins is very high against it.
>>>>
>>>> Keep in mind that "YOU", the typical user are just collateral
>>>> damage -
>>>> the target of systemd is the cloud. Fast boot, use it and and then
>>>> throwaway the image when done is the target. Keeping an image
>>>> running
>>>> reliably for months is not a priority any longer (check out the use
>>>> of
>>>> "chaosmonkey" in the data centre). When people like gnome (another
>>>> bunch of losers :) jumped on board it has twisted the market towards
>>>> something that's just not appropriate for most individual users. I
>>>> dont
>>>> think I can hold out forever, but will do do so until its no longer
>>>> viable.
>>>>
>>>> Dont like where your distro is going - choose another or build your
>>>> own
>>>> - give up and follow the sheep, you are lost!
>>>>
>>>> From a happy lxde, moving to lxqt, eudev and openrc user :)
>>>> BillK
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> On 08/09/14 06:13, Hani Jabr wrote:
>>>> > It's not a couple of seconds, it's a few minutes when you have
>>>> multiple applications that take time to start up, but can start in
>>>> parallel. That is important on production systems.
>>>> >
>>>> > Systemd seems like a rubbish implementation of something that's
>>>> long overdue on Linux. Every unix except AIX has implemented
>>>> something similar.
>>>> >
>>>> > Hani
>>>> >
>>>> >
>>>> >
>>>> >> On 7 Sep 2014, at 23:49, Alexander <alex at spottedmouse.com
>>>> <mailto:alex at spottedmouse.com>> wrote:
>>>> >>
>>>> >> Found some more details:
>>>> >>
>>>> >> http://www.tecmint.com/systemd-replaces-init-in-linux/
>>>> >>
>>>> >> I think this article makes a good case against systemd. Why do
>>>> we need
>>>> >> all this extra complexity for a couple of seconds we save during
>>>> >> startup. Since when is the startup time a measure for anything.
>>>> Maybe I
>>>> >> am getting too old. Have fond memories of uptime being a
>>>> measure for
>>>> >> things. Reminds me a little of the time when a new version of
>>>> windows
>>>> >> was released, which had a faster startup time as a major
>>>> feature.
>>>> >>
>>>> >>
>>>> >>> On 03/09/14 14:56, Alexander wrote:
>>>> >>> Just ran across : http://boycottsystemd.org/ and thought
>>>> fellow
>>>> pluggers
>>>> >>> may be interested as well.
>>>> >>> _______________________________________________
>>>> >>> PLUG discussion list: plug at plug.org.au <mailto:
>>>> plug at plug.org.au>
>>>> >>> http://lists.plug.org.au/mailman/listinfo/plug
>>>> >>> Committee e-mail: committee at plug.org.au
>>>> <mailto:committee at plug.org.au>
>>>> >>> PLUG Membership: http://www.plug.org.au/membership
>>>> >>
>>>> >> _______________________________________________
>>>> >> PLUG discussion list: plug at plug.org.au <mailto:plug at plug.org.au
>>>> >
>>>> >> http://lists.plug.org.au/mailman/listinfo/plug
>>>> >> Committee e-mail: committee at plug.org.au
>>>> <mailto:committee at plug.org.au>
>>>> >> PLUG Membership: http://www.plug.org.au/membership
>>>> > _______________________________________________
>>>> > PLUG discussion list: plug at plug.org.au <mailto:plug at plug.org.au>
>>>> > http://lists.plug.org.au/mailman/listinfo/plug
>>>> > Committee e-mail: committee at plug.org.au
>>>> <mailto:committee at plug.org.au>
>>>> > PLUG Membership: http://www.plug.org.au/membership
>>>> >
>>>>
>>>> _______________________________________________
>>>> PLUG discussion list: plug at plug.org.au <mailto:plug at plug.org.au>
>>>> http://lists.plug.org.au/mailman/listinfo/plug
>>>> Committee e-mail: committee at plug.org.au <mailto:
>>>> committee at plug.org.au>
>>>> PLUG Membership: http://www.plug.org.au/membership
>>>>
>>>>
>>>>
>>>>
>>>> --
>>>> "The ecological crisis is a moral issue." PJP 2nd
>>>>
>>>>
>>>> _______________________________________________
>>>> PLUG discussion list: plug at plug.org.au
>>>> http://lists.plug.org.au/mailman/listinfo/plug
>>>> Committee e-mail: committee at plug.org.au
>>>> PLUG Membership: http://www.plug.org.au/membership
>>>>
>>>
>>> _______________________________________________
>>> PLUG discussion list: plug at plug.org.au
>>> http://lists.plug.org.au/mailman/listinfo/plug
>>> Committee e-mail: committee at plug.org.au
>>> PLUG Membership: http://www.plug.org.au/membership
>>>
>>
>>
>
> --
> Dolphins are so intelligent that within a few weeks they can
> train Americans to stand at the edge of the pool and throw them
> fish.
>
> _______________________________________________
> PLUG discussion list: plug at plug.org.au
> http://lists.plug.org.au/mailman/listinfo/plug
> Committee e-mail: committee at plug.org.au
> PLUG Membership: http://www.plug.org.au/membership
>
--
Onno Benschop
()/)/)() ..ASCII for Onno..
|>>? ..EBCDIC for Onno..
--- -. -. --- ..Morse for Onno..
If you need to know: "What computer should I buy?" http://goo.gl/spsb66
ITmaze - ABN: 56 178 057 063 - ph: 04 1219 8888 -
onno at itmaze.com.au
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.plug.org.au/pipermail/plug/attachments/20140922/7e0ea5e0/attachment.html>
More information about the plug
mailing list