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<div class="moz-cite-prefix">The following caught my attention too.
<br>
<br>
On 06/17/2015 10:24 AM, Stephen Potter wrote:<br>
</div>
<blockquote cite="mid:5581832C.3040304@unixsa.net" type="cite">
<pre wrap="">With so much of the world now virtualized or (dare I say) cloud-based,
when comes the point that we no longer need generic OSes? When does the
hypervisor become the OS, and the application start to include
everything it needs to run on the hypervisor directly? ...
</pre>
</blockquote>
<br>
See below for bi-level op sys. <br>
<br>
<blockquote cite="mid:5581832C.3040304@unixsa.net" type="cite">
<pre wrap=""> ... With the
hypervisor handling the abstraction of most of the hardware, including
to a large extent process scheduling and memory management even, the
guest OS becomes much simpler. There is no longer a need for the guest
to support features such as page sharing or garbage collection. It
doesn't need a robust networking stack with all of the lower level
protocol support.</pre>
</blockquote>
<br>
Keep in mind that hypervisors commonly support "para" or "full"
(lately "both" more and more). <br>
Para-virtualization is especially helpful for stand-alone apps. <br>
<br>
Gotta talk about the bigger virtualization story. <br>
The mainframe hypervisor is truly incredible. <br>
I frequently rattle on about it. There are typically two responses:
<br>
For those who know "z" (and maybe actually *like* it) it's preaching
to the choir. <br>
For those who don't know it (maybe don't like it, or at least don't
like/trust IBM) it's dear-in-the-headlights. <br>
Bummer. <br>
<br>
KVM is just barely beginning to pick-up some of the features of
z/VM, things like sharing a chunk of memory across guests. <br>
<br>
There's so much more to be done with hypervisors, but the market is
passing them. <br>
Hypervisors are more secure than containers, but convenience trumps
security. <br>
Well ... there's also performance. <br>
<br>
Containers outperform hypervisors. <br>
Para-virt outperforms full-virt. (with less risks than containers) <br>
I AM NOT slamming containers. <br>
<br>
But ... key point from Stephen's comment: <br>
Prior to popular contemporary virtualization, IBM's "VM" was a <b>bi-level
operating system</b> product. The hypervisor served the kernel
role and two or three reduced guest op sys served the "user space"
role. The hypervisor could always go full-virt, but these
specialized guest systems leaned on para-virt so they could focus on
"user space" requirements. Very nice. <br>
<br>
<br>
<br>
<div class="moz-cite-prefix">On 06/17/2015 12:27 PM, Scott Merrill
wrote:<br>
</div>
<blockquote
cite="mid:6FD377BA-DB6F-41E4-AD1E-F864476EF40D@skippy.net"
type="cite">
<pre wrap="">Have you seen CoreOS or Project Atomic?
<a moz-do-not-send="true" class="moz-txt-link-freetext" href="https://coreos.com/">https://coreos.com/</a>
<a moz-do-not-send="true" class="moz-txt-link-freetext" href="http://www.projectatomic.io/">http://www.projectatomic.io/</a>
Both extend the notion of Just Enough OS (which you may be familiar with from Ubuntu: <a moz-do-not-send="true" class="moz-txt-link-freetext" href="https://en.wikipedia.org/wiki/Ubuntu_JeOS">https://en.wikipedia.org/wiki/Ubuntu_JeOS</a>).</pre>
</blockquote>
<br>
There's so much more to be done with hypervisors. (Is there an echo
in here?) <br>
Reduced systems (JEOS) is understated in that context. We can get he
bi-level op sys effect from these critters, and without IBM vendor
lock-in and without limiting hardware. (KVM runs on X86, mainframe,
POWER, and now ARM) <br>
<br>
TRULY AWESOME STUFF <br>
<br>
<br>
<div class="moz-cite-prefix">On 06/17/2015 11:37 AM, Judd Montgomery
wrote:<br>
</div>
<blockquote cite="mid:5581943D.5060101@jpilot.org" type="cite">
<div class="moz-text-plain" wrap="true" graphical-quote="true"
style="font-family: -moz-fixed; font-size: 12px;"
lang="x-western">
<pre wrap="">On 06/16/2015 09:46 PM, Rick Troth wrote:
</pre>
<blockquote type="cite" style="color: #000000;">
<pre wrap=""><span class="moz-txt-citetags">> </span>As for me, I've been griping lately about two or three trends,
<span class="moz-txt-citetags">> </span>especially in Linux. Would like to think that my whining is more due
<span class="moz-txt-citetags">> </span>to love of simplicity than from loathing "who moved my cheese?".
<span class="moz-txt-citetags">></span>
</pre>
</blockquote>
<pre wrap="">
Me too! I'm thinking about a project to replace systemd with emacs. <span class="moz-smiley-s1" title=":-)"></span>
Judd
</pre>
</div>
</blockquote>
<br>
In a JEOS context and/or a para-virt dependent "guest", replacing
SystemD with *anything* is justified. <br>
<br>
Few admins realize that they can replace '<font face="Courier New,
Courier, monospace">init</font>' on any Linux system (really any
POSIX system) with their own invention. They *can* and sometimes
they *should*. (For varying values of "sometimes", you understand.)
<br>
<br>
Bi-level op sys and JEOS are places where "small is beautiful". <br>
<br>
-- R; <><<br>
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