Xen users - Oct 2012 - Longtime *nix user/admin planning on making the move to Xen

I''ve been meaning to change my local home server to several virtual
machines running under Xen.  Primarily to better serve my home/office network
needs.  I''ve been running a Gentoo server that''s become rather
cluttered (smtp,imap,pop,http,https,ossec-hids,firewall,router,packet
inspection,workstation, backup server....... bloody everything!) so if I want to
work on anything or need to reboot everything goes down of course.

My first thought was to make my life simple and go with the XCP iso
installation, however according to this:
http://wiki.xen.org/wiki/Xen_/_XCP_/_XCP_on_Linux_Overview that doesn''t
support 64-bit and I''ve got 16GB ram. I could install from packages it
seems but once I get to that point I''m thinking I might as well install
Xen rather than XCP and have the latest hypervisor.

As a current Gentoo user I''m tempted to stick with that though
I''m not against Debian/Ubuntu or other distros either.  Perhaps there
are other compelling reasons to go with another distro?

I''m planning on moving a mythtv backend into a domU, so I''ll
need to compile kernel support for the pcHDTV HD-5500 tuner card. Which I
suspect means custom kernel build anyway? Presumably I can use the PCI
passthrough feature to make the domU system see the 5500..hopefully.

I have a lot of experience with virtualization (VMWare and Hyper-V) just none
with Xen.. I''ve been reading the wiki and I''m fairly sure I
can get setup without any trouble.

Kinda hoping for a gut check/tips/advice from users that might help me avoid
doing the wrong things.  I''m not in a big hurry and pretty much
prepared to have to redo things if I go down the wrong path ;-)

Thanks for any tips/advice/hints...

Hello,

I have never tried XCP so I can''t give you any advice there, but unless
you
are using more than one physical machine Xen with the xl toolstack should
work fine.


I recommend sticking to the distribution you feel more comfortable using,
especially if time is not a factor.  Getting your system working as desired
will probably come down to trial and error.

I can only think of two compelling reasons to go with another distribution.
 Abundance of documentation, and greater support.  Picking a more commonly
used distribution means more guides are available and xen-users list may
have more able-bodies to answer questions.


Dom0 may require a custom kernel anyways, but with passthrough only DomU
needs the HD Tuner driver.  Dom0 just needs the BDF to identify & pass the
device.


If you are considering Debian you might find this useful:
http://wiki.xen.org/wiki/Comprehensive_Xen_Debian_Wheezy_PCI_Passthrough_Tutorial

Best of luck,

~Casey

On Wed, Oct 31, 2012 at 1:18 PM, Braindead <Braindead@unruleable.org>
wrote:
> I''ve been meaning to change my local home server to several
virtual
> machines running under Xen.  Primarily to better serve my home/office
> network needs.  I''ve been running a Gentoo server that''s
become rather
> cluttered (smtp,imap,pop,http,https,ossec-hids,firewall,router,packet
> inspection,workstation, backup server....... bloody everything!) so if I
> want to work on anything or need to reboot everything goes down of course.
>
> My first thought was to make my life simple and go with the XCP iso
> installation, however according to this:
> http://wiki.xen.org/wiki/Xen_/_XCP_/_XCP_on_Linux_Overview that
doesn''t
> support 64-bit and I''ve got 16GB ram. I could install from
packages it
> seems but once I get to that point I''m thinking I might as well
install Xen
> rather than XCP and have the latest hypervisor.
>
> As a current Gentoo user I''m tempted to stick with that though
I''m not
> against Debian/Ubuntu or other distros either.  Perhaps there are other
> compelling reasons to go with another distro?
>
> I''m planning on moving a mythtv backend into a domU, so
I''ll need to
> compile kernel support for the pcHDTV HD-5500 tuner card. Which I suspect
> means custom kernel build anyway? Presumably I can use the PCI passthrough
> feature to make the domU system see the 5500..hopefully.
>
> I have a lot of experience with virtualization (VMWare and Hyper-V) just
> none with Xen.. I''ve been reading the wiki and I''m fairly
sure I can get
> setup without any trouble.
>
> Kinda hoping for a gut check/tips/advice from users that might help me
> avoid doing the wrong things.  I''m not in a big hurry and pretty
much
> prepared to have to redo things if I go down the wrong path ;-)
>
> Thanks for any tips/advice/hints...
>
> _______________________________________________
> Xen-users mailing list
> Xen-users@lists.xen.org
> http://lists.xen.org/xen-users
>

_______________________________________________
Xen-users mailing list
Xen-users@lists.xen.org
http://lists.xen.org/xen-users

On Wed, 31 Oct 2012 14:37:01 -0400 Casey DeLorme <cdelorme@gmail.com>
wrote:
> Hello,
> 
> I have never tried XCP so I can''t give you any advice there, but
> unless you are using more than one physical machine Xen with the xl
> toolstack should work fine.
That''s about what I gathered.  XCP seems to be nicely setup for
migration/HA and sounds like it has different maybe ''nicer''
tools.
> I recommend sticking to the distribution you feel more comfortable
> using, especially if time is not a factor.  Getting your system
> working as desired will probably come down to trial and error.
> 
> I can only think of two compelling reasons to go with another
> distribution. Abundance of documentation, and greater support.
> Picking a more commonly used distribution means more guides are
> available and xen-users list may have more able-bodies to answer
> questions.
> 
> 
> Dom0 may require a custom kernel anyways, but with passthrough only
> DomU needs the HD Tuner driver.  Dom0 just needs the BDF to identify
> & pass the device.
Thanks.  I''m pretty sure the driver for this capture card is built into
the kernel now.  I''ve got a system that runs it now so I have a kernel
config reference.

Thanks for the info.. I think I''m at least mostly on the right path.

XCP definitely supports 64 bits.  The 32 bit issue is with the Dom0. 
Don''t
confuse the Dom0 with the DomU.  The 32 bit Dom0 does not limit the 64 bit
hypervisor from using all of the memory.  The DomU can all be 64 bit.  I
have used XCP on servers with 96GB each, and XCP works great.  Several of
the DomU each have 16GB allocated to them.  Those DomU are CentOS 64 bit.  

-----Original Message-----
From: xen-users-bounces@lists.xen.org
[mailto:xen-users-bounces@lists.xen.org] On Behalf Of Braindead
Sent: Wednesday, October 31, 2012 12:19 PM
To: xen-users@lists.xen.org
Subject: [Xen-users] Longtime *nix user/admin planning on making the move
toXen

I''ve been meaning to change my local home server to several virtual
machines
running under Xen.  Primarily to better serve my home/office network needs.
I''ve been running a Gentoo server that''s become rather
cluttered
(smtp,imap,pop,http,https,ossec-hids,firewall,router,packet
inspection,workstation, backup server....... bloody everything!) so if I
want to work on anything or need to reboot everything goes down of course.

My first thought was to make my life simple and go with the XCP iso
installation, however according to this:
http://wiki.xen.org/wiki/Xen_/_XCP_/_XCP_on_Linux_Overview that doesn''t
support 64-bit and I''ve got 16GB ram. I could install from packages it
seems
but once I get to that point I''m thinking I might as well install Xen
rather
than XCP and have the latest hypervisor.  

As a current Gentoo user I''m tempted to stick with that though
I''m not
against Debian/Ubuntu or other distros either.  Perhaps there are other
compelling reasons to go with another distro?

I''m planning on moving a mythtv backend into a domU, so I''ll
need to compile
kernel support for the pcHDTV HD-5500 tuner card. Which I suspect means
custom kernel build anyway? Presumably I can use the PCI passthrough feature
to make the domU system see the 5500..hopefully.

I have a lot of experience with virtualization (VMWare and Hyper-V) just
none with Xen.. I''ve been reading the wiki and I''m fairly sure
I can get
setup without any trouble.

Kinda hoping for a gut check/tips/advice from users that might help me avoid
doing the wrong things.  I''m not in a big hurry and pretty much
prepared to
have to redo things if I go down the wrong path ;-)

Thanks for any tips/advice/hints...

_______________________________________________
Xen-users mailing list
Xen-users@lists.xen.org
http://lists.xen.org/xen-users

> -----Original Message-----
> From: xen-users-bounces@lists.xen.org
[mailto:xen-users-bounces@lists.xen.org] On
> Behalf Of Braindead
> Sent: Wednesday, October 31, 2012 1:19 PM
> 
> My first thought was to make my life simple and go with the XCP iso
installation,
> however according to this:
> http://wiki.xen.org/wiki/Xen_/_XCP_/_XCP_on_Linux_Overview that
doesn''t support
> 64-bit and I''ve got 16GB ram.
XCP has a 32-bit Dom0.  You don''t need a 64-bit Dom0 to use all your
RAM, just a 64-bit hypervisor.

You may want to install Xen on your own distribution regardless to get the
latest-and-greatest hypervisor and tools, but I wouldn''t go through the
trouble just to get a 64-bit Dom0--you probably don''t need it.

-Jeff

On Wed, 31 Oct 2012 21:17:36 +0000 Jeff Sturm <jeff.sturm@eprize.com>
wrote:
> > -----Original Message-----
> > From: xen-users-bounces@lists.xen.org
> > [mailto:xen-users-bounces@lists.xen.org] On Behalf Of Braindead
> > Sent: Wednesday, October 31, 2012 1:19 PM
> > 
> > My first thought was to make my life simple and go with the XCP iso
> > installation, however according to this:
> > http://wiki.xen.org/wiki/Xen_/_XCP_/_XCP_on_Linux_Overview that
> > doesn''t support 64-bit and I''ve got 16GB ram.
> 
> XCP has a 32-bit Dom0.  You don''t need a 64-bit Dom0 to use all
your
> RAM, just a 64-bit hypervisor.
> 
> You may want to install Xen on your own distribution regardless to
> get the latest-and-greatest hypervisor and tools, but I wouldn''t
go
> through the trouble just to get a 64-bit Dom0--you probably don''t
> need it.
Thanks for the clarification on that. 

-- 
Send some filthy mail.

Hi.

El 31/10/12 11:18, Braindead escribió:
> My first thought was to make my life simple and go with the XCP
(Maybe some Xen developer will read this and even wish to do 
corrections. In any case, this is a feedback.)

In my own very personal perception, XCP is a nice system to be 
integrated into an ecosystem, where you have multiple nodes that come 
and go, orchestration solution, maybe centralized storage, etc. In the 
other hand, when it''s about a single (or few) host system with local 
storage, administrated by the same person who is the principal user, a 
regular Linux distribution with Xen is more suitable.

They say SuSE, as distribution, is a good starting point, since they are 
very involved in Xen development.
Personally, my distribution of choice has been Debian, which has been 
working marvelously as Dom0 and as DomU in many roles. The package 
xen-tools has everything needed to get started and do proof-of-concept 
tests.
> I''m planning on moving a mythtv backend into a domU, so
I''ll need to
> compile kernel support for the pcHDTV HD-5500 tuner card. Which I
> suspect means custom kernel build anyway? Presumably I can use the
> PCI passthrough feature to make the domU system see the 5500..hopefully.
Make sure your hardware has IOMMU support, which is needed for for PCI 
Passthrough.
The custom kernel is not a problem at all. The most regular way to boot 
a PV guest (at least in Debian) is taking the kernel imiage and initrd 
form the Dom0 system, but you can install any (xen enabled) kernel 
within a DomU and boot it using pygrub or something similar.

The obvious advice would be to keep Dom0 as clean as possible, moving 
services and applications to DomUs. Customize (and keep reference of) 
the xen-tools configs and templates, so you can get a very reproducible 
results each time you do a new deploy.

I always install early a cache/proxy server to use as distribution 
repository ("approx" for Debian or Ubuntu), so when I deploy a new VM 
with xen-create-image using debootstrap, it comes out fast and fresh.

-- 
Alexandre Kouznetsov