Topic: How to install SME 7.3 under Xen virtualization.

[arne]

I have installed SME 7.3 as host and guest operating system with Vmware and this works smoothly and without a bug.

To get some more reeferance an the subject I like to test out SME 7.3 running as a guest operating system under Xen as well.

Installed Centos 5.1/64 with Xen and used this guide: http://www.howtoforge.com/centos_5.0_xen

Installed a virtual Centos 5.1/32 under Xen and this worked ok.

Then tried to install SME 7.3 but the virtuall installer just came up with the message that the proper files were not found:

From the guest operation dialogue:

[root@pc-00241 ~]# virt-install
What is the name of your virtual machine? sme73
 How much RAM should be allocated (in megabytes)? 256
 What would you like to use as the disk (path)? /vm/vm2.img
 How large would you like the disk (/vm/vm2.img) to be (in gigabytes)? 8
 Would you like to enable graphics support? (yes or no) no
 What is the install location? http://smemirror.fullnet.co.uk/releases/7.3/smeos/i386/


Starting install...
ERROR:  Could not find an installable distribution the install location

Reason for selecting a internetbased installation was because this method worked with the Centos 5.1 guest installation.
( http://wftp.tu-chemnitz.de/pub/linux/centos/5.1/os/i386/ )

My first thought and believe about this was that this actually were just the more general question: "How to install SME 7.3 over the net ?"

I then remembered that I think that the Linux kernel has to be customized for Xen virtualization.

I did then try to install SME 8.0 beta as it is based on Centos 5. Did not work.

Also tried to mount tne SME 7.3 CD to install from CD. Did not work.

Does anybody has some ideas if it is possible to install SME 7.3 under Xen ?

Could it eventuelly be possible to ad on an extra kernel or replace the old one (using the 8.0 beta ?) ?

Anybody who knows ?

By the way - everything that should work does work with Vmware server already, but it would be just interesting to see if the Xen as an open source product could be used as well ..

[stephen noble]

http://bugs.contribs.org/show_bug.cgi?id=3663

[arne]

Thanks for this information. It looks like the person posting the bug is using a slightly different installation method than me. My installation does not even start up so that I am able to get an incorrect password.

I think I red in the Xen dokumentation that a standard Linux kernel will hot run as guest under Xen, so that it will be requred to use a kernel that is compiled espesially for Xen.

I wonder if this could be the common reason ?

From the Xen FAQ:

1.3. Which OSes run on Xen?
To achieve such high performance, Xen requires that OSes are ported to run on it. See the Current status of OS ports

http://wiki.xensource.com/xenwiki/OSCompatibility

Will a standard Linux 2.6 kernel run ??

Is this actually a guide how to install the SME 7.3 under Xen and will it also include to replace the kernel with a Xen modified kernel ? (I have to admit I do not understand the guide completely.)

http://wiki.centos.org/HowTos/Xen/MoveNative2DomU
 

[arne]

Conclusion about SME server 7.3/8.0 and Xen:

The SME 7.3 and SME 8.0 does not have "kernel compability" with the Xen runtime enviroment, so the SME servers can not work under Xen without a kernel modification.

Centos 5.1/64 is rather easy to set up as a Xen host and as a guest. The way I think it works is that the Centos 5.1/64 distro is equiped with more than one kernel, and under installation it is detected if it is a question of a Xen "runtime" or virtualization envirinent, and if it is the Xen variant of the kernel is used.

32 bit varient of the Centos 5.1 has been tested as guest, so it is not a requirement that the guest is 64 bit system, but I belive that if the SME 8.0 shall support a Xen installation, it will be required to keep the multiple kernel arrangement of the Centos 5.1

(At least I hope I understand these things in some way.)

As it will be to difficult and time consuming to replace the SME server kernel with a Xen prepared variant, I think I park this project here.

Vmware server fits by the way much bether with the product philosophy of the SME server as a easy to manage and yet powerful system. Xen gives a more "low lewel but effective" style of all its arrangements.

It would be intersiting if there is some other persons with some other conclusions.

[slords]

The SME 7.3 and SME 8.0 does not have "kernel compability" with the Xen runtime enviroment, so the SME servers can not work under Xen without a kernel modification.

[...]

As it will be to difficult and time consuming to replace the SME server kernel with a Xen prepared variant, I think I park this project here.

SME and xen are completely compatible.  That is how I do all my testing.  There are also a few other testers that are using xen installs of sme. 

[arne]

Interesting.

But how do you do that installation ?

At the Centos 5.1 there is a number of kernels where some are marked -xen. When you are running xen at host the -xen variant of the host is running. This I think I noticed. I also belived there was a customized kernel at the guest, but I might be wrong about that .. ??!!

When I did a centos 5.1/64 installation and just selected "support for virtualization", the Xen demon, etc went into place. I then installed a Centos 5.1 as a guest and this wa not a problem. I used this guide:

http://www.howtoforge.com/centos_5.0_xen

When I tried to install the SME 7.3 and 8.0 I anly got the message that there was no innstallable files.

What would be the proper method for installing SME server under Xen when (if) the Xen demon and enviroment is there ?

I used this tool at Centos 5.1: "virt-install"

Could it be that the SME server is just not compatible with that tool and that there is required some other "manual method" ? Or possible something else ?

I am rather curious to give it a new try .. 

[tec]

Hi Arne,
maybe you can go the route via HVM-Domain for installation, if you have and HVM-capable hardware, and then later convert the domain to a paravirtuallized one
These are my instructions when I installed SME on a Debian Dom0
http://forums.contribs.org/index.php?topic=38802.0;topicseen
Cheers

[arne]

tec -> Thanks a lot for this info.

If the small and simple procedure dont work I will try the bigger one.

slords had this intersting post in this tread:

If you have a RHEL5/CentOS5 box you can also do this which is a whole lot easier and quicker:

virt-install -n sme -r 512 -f /dev/main/sme \
-b xenbr0 --nographics -l \
http://distro.ibiblio.org/pub/linux/distributions/smeserver/releases/7/smeos/i386 \
-x 'ksdevice=link ip=dhcp selinux=0 text'


Where /dev/main/sme is the empty lvm you have created to house your sme installation.  You can also change the url to point to a closer mirror or to loop mounted copy of the iso.

This will install sme and create the /etc/xen/sme file correctly for you.  You won't need to connect with vnc and won't have to tweak anything afterwords either.  I'm not sure if other distros contain the virt-install but I do know that el5/cos5 do.

This lead to exactely the same error messages as I had:

Starting install...
ERROR:  Could not find an installable distribution the install location

No one were able to solve this problem in the last tread.

I wonder if this sentece in the post of slords could have the key:

Where /dev/main/sme is the empty lvm you have created to house your sme installation.

What does this mean, and how do I make an empty lvm ?

Does it have anything to to with this:

http://www.gweep.net/~sfoskett/linux/lvmlinux.html ?
http://www.howtoforge.org/linux_lvm

slords -> do you have a few words ?

Possibly something here ?:
http://www.centos.org/modules/newbb/viewtopic.php?topic_id=8041
http://www.nikhef.nl/pub/projects/grid/gridwiki/index.php/Xen_on_CentOS_5_-_Notes

[tec]

What does this mean, and how do I make an empty lvm ?

Maybe I can help.
You can install a Xen paravirtualized Domain in two ways. One would be in a file container similiar to the VMware image files. The other and recomended one from a performance standpoint is to install it inside an  LVM-Volume.
If you want to install it in an LVM Volume. You need an free partition on your harddrive which is partioned for LVM and has usually a name lets name "mygreatlvmvolume"
You can make it with the pvcreate commando.
On my machine a pvscan give the following output:
PV /dev/sda5   VG mygreatlvmvolume   lvm2 [372,52 GB / 45,29 GB free]


Then you can create within this partition a specific volume

lvcreate -n sme_lv -L 60GB mygreatlvmvolume <<<this creates an logical volume where your sme installation will go inside.
mkfs -t ext3 /dev/mygreatlvmvolume/sme_lv

after this you type lvscan in your command prompt and this will show something like this:
/dev/mygreatlvmvolume/sme_lv' [60,00 GB] inherit

Cheers

[arne]

Thanks.

When done as a Centos 5.1 more or less automated installation of a "gest" it produces those image files simular to vmware. At least it is a simple way for testing.

I will do a new installation of the host system and this time I wil let there be some unpartioned space there so I can try this other method.

Arne.

[tec]

Arne take a look at the Benchmark comparison from Filebased to LVMbased Virtual Machines
http://www.nospam-domain.de/wiki/bnmsp/xenserver

I suppose that with this Info the reinstallation from you Host will go easier

[arne]

tec -> Where do this name come from: mygreatlvmvolume
(Do I in some way install it ?)

I did not have success by installing SME at Centos 5.1 at all. Yesterday it worked with Centos 5.1 as "guest".

It would be nice to have a some kind of howto for the SME server, to do it as simple as possible, and the guide on the net will not work for the SME server.

I will try to study your method a bit further on.

By the way, the installation and use of Vmserver is close to nothing compared with Xen. With the SME 7.3 and Vmware you can speak with someone at ten o'clock and agree that you will have everything set up and running at twelve o'clock. This does not seem to be the case for the Xen alternative.

****
Found something here:
http://www.linuxtopia.org/online_books/rhel5/rhel5_xen_virtualization/index.html

[tec]

Hi Arne,
you need somewhere on your Disk empty space. Then start fdsik and make in this empty space a new partition, lets assume  it  is /dev/sdb. And then when asked which type it should be you will select "Linux LVM" the Hexcode for this  8e. Then you need to:

Code: [Select]

pvcreate /dev/sdb1 This now your "Physical Volume". After this you have a partition which is reserved for LVM-Volumes. Now you will need to create an an Volumegroup on this Physical Volume.

Code: [Select]

vgcreate mygreatlvmvolume /dev/sdb1
After this you are now able to create Logical-Volumes inside your Volumegroup with

Code: [Select]

lvcreate -n sme_lv -L 60GB mygreatlvmvolume and now format this volume with

Code: [Select]

mkfs -t ext3 /dev/mygreatlvmvolume/sme_lv

If this still doesn't work, try my HowTo. There you need to do all the steps by Handy and you will do but this should give you a working SME-inside Xen installation.

[arne]

Thanks for the information 

I have now parked the Xen virtualization project a litle bit to do the "SME on 64 bit host via vmware server" project. Reason is that I believed there was some kind of incompability between the SME repositories on the net and the Xen server, at lest when it comes to the Centos related installation procedures (??!!). I will use some time later on to look into this problem.

By the way here is some reading for later use:
http://www.centos.org/docs/5/html/5.1/Virtualization_Guide/
http://www.centos.org/docs/5/html/5.1/Virtual_Server_Administration/

And I also found something in the Centos/RedHat documentation (Virtualization guide chapter 4):

Note

If your system CPU architecture is ia64, you need to manually install the xen-ia64-guest-firmware package to run a fully virtualized guest. This package is provided in the Supplementary CD and is not installed by default.

On my newest hardware I tried to install from a sme.iso and this way the installation started, but was then hanging after the virtual machine was created. This match with the Centos note, I think.

This note could be the explanation if it works on Debian but not on a 64 bit Centos. I did not use this extra Centos package.

********
OK still made an atempt and run into the problem that the required rpm package is not publically available (???)
http://rhn.redhat.com/errata/RHEA-2007-0702.html  (Or is it ?)

Also found on the net:

"If fully virtualized (HVM) domains are required, the IA-64 guest firmware package will also need to be installed from the Supplementary CD-ROM: Supplementary/xen-ia64-guest-firmware-1.0.0-8.ia64.rpm"

Supplementary CD ROM ??

[arne]

The problem about installing SME 7.3 on Xen/Centos5.1/64 apeared to be related to some buggy Centos 5.1 packets.

The SME 7.3 runns like a dream under Xen and on a Centos 64 platform, and it looks like it performs even bether than when running on Vmware same platform.

There is absolutely no errors to the SME 7.3 that prevent it to run as a VM under Xen. (.. As far as I have been able to test it out until now.)

Slords is right in his post above - A virtual SME 7.3 on Xen works wery well.

... And the easy guide that did work:

http://www.cyberciti.biz/tips/rhel-centos-xen-virtualization-installation-howto.html