Slackware 14.2 Under XenServer 7.1

I've always had a networking problem with Slackware as a guest VM under Citrix XenServer (or Citrix Hypervisor, I guess is what they call it these days).  I still prefer Slackware as a desktop and so I set about solving this again recently - this time I would not be thwarted!

I ran across this article: How do I disable 8139too network driver... because lsmod lead me to search for 8139too networking module.  This was an Ubuntu article, so, I'll transmorgify it a bit for Slackware users.   The first thing it suggested was to blacklist 8139 in the modules.  Like the author of this I did not have any luck with that.  It was suggested you use the 8139cp instead (cool!  I didn't even know of its existence before this article).

# lsmod | grep 8139


This revealed 8139too in use and bound with mii, so...

# rmmod 8139too
# rmmod mii
# modprobe 8139cp
# modprobe mii
# /etc/rc.d/rc.inet1 restart

At this point, I had, for the first time ever as a Slackware XenServer guest, a working eth0!

In order to keep it (and use less resources) I created a smaller kernel /boot/initrd.gz by running mkinitrd.

# /usr/share/mkinitrd/mkinird_command_generator.sh

I appended :8130cp to the suggested mkinitrd script:

# mkinitrd -c -k 4.4.14 -f ext4 -r /dev/sda2 -m jbd2:mbcache:ext4:8139cp -u -o /boot/initrd.gz

This seemed to work nicely so I doctored up the boot area a bit:

# cd /boot
# rm System.map
# ln -s System.map-generic-4.4.14 System.map
# rm config
# ln -s config-generic-4.4.14 config

Then I added a section to the /etc/lilo.conf:

 image = /boot/vmlinuz-generic
   label = Slackware
   initrd = /boot/initrd.gz
   root = /dev/sda2
   read-only

And I always add default = Slackware before running lilo -v.

After that, I rebooted and had a Slackware install with a nice lean kernel with a eth0 running as a guest VM under Citrix XenServer (or Hypervisor - I can't get used to that!).
   

  

 

Slackware and LXC

I have a fresh Slackware 14.2 I've been enjoying since it came out this month.  I needed a hyper-visor and was getting ready to add Xen (the hyper-visor of choice on Slackware).  I like Xen, but I knew the compile times for the Slackbuilds and it's dependencies would probably take more time than I had at the moment.  Then I remembered LXC.  It comes with.

I didn't know much about LXC so did some quick reading.  They say "it's similar to Docker but easier" - I like the sound of that.  So I check it out.  It's EXACTLY like Solaris containers!  Which I've been using for over 10 years - but, again, easier!  It's pretty slick!  And it installs by default on Slackware 14.2 but there's a few things you need to change.

ON THE HOST

Edit the /etc/rc.d/rc.inet1.conf

Slackware does not have a bridged network device by default BUT it does have it defined and commented out.  I found this works nicely except I was expecting my host interface to use eth0 and lxc guest to use br0.  It was not what I expected but it works fine!

# Example of how to configure a bridge:
# Note the added "BRNICS" variable which contains a space-separated list
# of the physical network interfaces you want to add to the bridge.
IFNAME[0]="eth0"
BRNICS[0]="br0"
#IPADDR[0]=""
#NETMASK[0]=""
USE_DHCP[0]="yes"
#DHCP_HOSTNAME[0]=""

Routing = Yes

You will, of course, need your host to route packets so

# chmod 755 /etc/rc.d/rc.ip_forward

And then start it or restart.  I like to restart to make sure everything is the way it needs to be before relying on it.  You could also just

# echo 0 > /proc/sys/net/ipv4/ip_forward

LXC Config

Really the only other thing you need to do is add a bit to /etc/lxc/default.conf.  This worked for me:

root@slacks:~# cat /etc/lxc/default.conf
lxc.network.type=veth
lxc.network.link=br0
lxc.network.flags=up

ON THE LXC GUEST

Just run netconfig and set a static address or DHCP and then restart rc.inet1.  

WHAT LXC GUEST?!!

Oh, I skipped that bit, eh?  Super simple.  Try this:
  
# lxc-create -n lxcguest -t /usr/share/lxc/templates/lxc-slackware
# lxc-start -n lxcguest -d
# lxc-console -n lxcguest  (it'll tell you how to login)

Now, run netconfig.  

What?!  You're already running Slackware on the host and you'd like to try something different?  Just run list the contents of  /usr/share/lxc/templates and then try one or a dozen of the other 18 pre-installed templates.  Like:

root@slacks:~# ls /usr/share/lxc/templates
lxc-alpine*     lxc-cirros*    lxc-openmandriva*  lxc-sparclinux*
lxc-altlinux*   lxc-debian*    lxc-opensuse*      lxc-sshd*
lxc-archlinux*  lxc-download*  lxc-oracle*        lxc-ubuntu*
lxc-busybox*    lxc-fedora*    lxc-plamo*         lxc-ubuntu-cloud*
lxc-centos*     lxc-gentoo*    lxc-slackware*


If you down like any of those, try something else with this command:

# lxc-create -t /usr/share/lxc/templates/lxc-download -n newguest

You will be given an even bigger choice.  Knowing Slackware and how stable it is, I would stay with the local choices to ensure that legendary stability stays as is (but that's just me). 

THE END

Well, that's all of my notes.  Postive comments and any kind of experiences with LXC are always welcome below.