Greetings,

As you may already know, Red Hat released Red Hat Enterprise Linux 7 on Tuesday 
(June 10th).  A while ago the two main CentOS developers got hired by Red Hat 
to work on CentOS because Red Hat is now the sponsor behind CentOS... like they 
are behind Fedora.  Anyway... the CentOS folks are working hard and fast to try 
to get CentOS 7 out ASAP... although they are going to keep their high release 
quality standards (it's as good as RHEL and as bad as RHEL, hehe).  Something 
new they are doing now is trying to be as transparent and public as possible.  
They have placed their build system in the open, all of the package code in 
git, etc.

On June 13th CentOS announced that they have made the initial built of (most 
of) the rpm packages for CentOS 7.  On June 14th they announced the build-tree 
was fairly complete including a boot.iso that could be used for a network 
install.  Anyway, for the full story, read http://seven.centos.org/.

I've been busy working with the "CentOS 7 Public QA" release making an 
installable LiveDVD (check) and making an OpenVZ OS Template (check).  The 
later is what this email is about.  I have uploaded 
"centos-7-pubqa-20140615.tar.xz" (and .asc GPG sig file) to the OpenVZ 
contributed OS Templates directory.  A few notes:

1) CentOS 5 uses SysV init.  CentOS 6 uses Upstart basically in SysV 
compatibility mode.  CentOS 7 uses systemd.  If you create a container from an 
OS Template named centos-{something} I think it'll use the current CentOS 
config scripts provided by vzctl... which probably won't work because of the 
big change in init systems.  CentOS 7 is a LOT like the last few releases of 
Fedora that have also been systemd-based... so what I did on my OpenVZ host 
where I wanted to use this centos-7-pubqa-20140615.tar.xz contributed OS 
Template was... make a symlink in /vz/templace/cache/ named 
fedora-19-x86_64.tar.xz that points to centos-7-pubqa-20140615.tar.xz.  Then 
when I used vzctl to create the container, I told it to use the fedora19 OS 
template.  Of course if you already have an OS Template named 
fedora-19-x86_64.tar.* make the symlink named something else and refer to it 
appropriately.  I asked for a clarification from Kir on that... because maybe 
I'm imagining the issue.

2) The current CentOS 7 Public QA build-tree does not provide 
/etc/yum.repos.d/centos*.repo files.  Why?  Because the location of the current 
build system and all of the rpm packages is in a temporary place and won't be 
finalized until the final release comes out.  In my OS Template I created 
/etc/yum.repos.d/centos-7-public-qa-20140615.repo that refers to the *CURRENT* 
location of all of the packages.  Doing that makes yum work... and you can 
install and remove software as desired.  I'm sure they will be updating the 
build-tree and package location quite a bit between now and final release... so 
if the current location goes away or there is a newer build... you'll have to 
update the .repo file to point to wherever it needs to point.  It was working 
fine when I uploaded it. :)

3) RHEL7 is only offered in a 64bit flavor... and as a result... the OS 
Template is 64bit.  It will not run on a 32bit OpenVZ host node.  Don't even 
try it.  It won't hurt anything but you'll get an error and if you don't know 
what the issue is, you'll probably go to IRC and bug people there about it... 
which would be a waste of everyone's time... but if you do do that... hopefully 
we'll be able to tell you what the problem is.  The OS Template name I gave was 
already long enough and I didn't want to add x86_64 to it... because people 
would probably think there was a missing i686 build coming.  There isn't.

4) How did I make this OS Template?  It was rather simple.  I created a CentOS 
7 KVM virtual machine installing from the network media currently available.  I 
did a minimal install.  Then I rsync'ed the contents of VM's virtual disks to 
an OpenVZ host node.  Then I made the minor changes needed... (not all but 
most) mentioned in the OpenVZ p2v wiki page.  Then I tar.xz'ed it up and 
plopped it in /vz/template/cache... made a container out of it... and it worked 
first attempt.  Then I cleaned it up by removing unneeded packages (grub2, 
kernel, firmware packages, unwanted services [firewalld, ipr*, etc], etc).  
Then I added a few things I like (httpd, screen, mc, nano, links, etc).  Then I 
tested it.  Then I made a new OS Template by tar.xz'ing up the container's 
directory.  Then I made a new container out of the new OS Template and tested.  
Works pretty darn well.  I'm sure there are some lingering dirs/files from 
packages I removed... and probably another handful or two of pa!
 ckages that could be removed to make it smaller but hey... it is ~98MB as a 
.tar.xz.  Installed it takes up slightly less than 700MB.  Not too bad for a 
first attempt.

If you have any comments or questions, just ask.  Enjoy!

TYL,
-- 
Scott Dowdle
704 Church Street
Belgrade, MT 59714
(406)388-0827 [home]
(406)994-3931 [work]

_______________________________________________
Users mailing list
Users@openvz.org
https://lists.openvz.org/mailman/listinfo/users

Reply via email to