Anvil! Tutorial 3

AN!Wiki :: How To :: Anvil! Tutorial 3

Warning: This tutorial is incomplete, flawed and generally sucks at this time. Do not follow this and expect anything to work. This warning will be removed when the tutorial is completed.

Warning: This tutorial is built on a guess of what Red Hat's Enterprise Linux 7 will offer, based on what the author sees happening in Fedora upstream. Red Hat never confirms what a future release will contain until it is actually released. As such, this tutorial may turn out to be inappropriate for the final release of RHEL 7. In such a case, the warning above will remain in place until the tutorial is updated to reflect the final release.

This is the third AN!Cluster tutorial built on Red Hat's Enterprise Linux 7. It improves on the RHEL 5, RHCS stable 2 and RHEL 6, RHCS stable3 tutorials.

As with the previous tutorials, the end goal of this tutorial is a 2-node cluster providing a platform for high-availability virtual servers. It's design attempts to remove all single points of failure from the system. Power and networking are made fully redundant in this version, along with minimizing the node failures which would lead to service interruption. This tutorial also covers the AN!Utilities; AN!Cluster Dashboard, AN!Cluster Monitor and AN!Safe Cluster Shutdown.

As it the previous tutorial, KVM will be the hypervisor used for facilitating virtual machines. The old cman and rgmanager tools are replaced in favour of pacemaker for resource management.

Before We Begin

This tutorial does not require prior cluster experience, but it does expect familiarity with Linux and a low-intermediate understanding of networking. Where possible, steps are explained in detail and rationale is provided for why certain decisions are made.

For those with cluster experience;

Please be careful not to skip too much. There are some major and some subtle changes from previous tutorials.

OS Setup

Warning: I used Fedora 17 at this point, obviously things will change, possibly a lot, once RHEL 7 is released.

If you find that the text scrolls off the top and bottom of the screen, and you can't adjust the monitor enough to fix it, you may need to disable modeset in the kernel. To do this, we need to add the command nomodeset to the GRUB_CMDLINE_LINUX line.

cp /etc/default/grub /etc/default/grub.orig
vim /etc/default/grub
diff -u /etc/default/grub.orig /etc/default/grub

--- /etc/default/grub.orig	2012-09-01 15:14:27.658992174 -0400
+++ /etc/default/grub	2012-09-01 15:14:39.136992153 -0400
@@ -1,5 +1,5 @@
 GRUB_TIMEOUT=5
 GRUB_DISTRIBUTOR="Fedora"
 GRUB_DEFAULT=saved
-GRUB_CMDLINE_LINUX="rd.md=0 rd.lvm=0 rd.dm=0 SYSFONT=True  KEYTABLE=us rd.luks=0 LANG=en_US.UTF-8"
+GRUB_CMDLINE_LINUX="rd.md=0 rd.lvm=0 rd.dm=0 SYSFONT=True  KEYTABLE=us rd.luks=0 LANG=en_US.UTF-8 nomodeset"
 #GRUB_THEME="/boot/grub2/themes/system/theme.txt"

Now to update grub2 itself, run the following;

grub2-mkconfig -o /boot/grub2/grub.cfg

Generating grub.cfg ...
Found linux image: /boot/vmlinuz-3.5.2-3.fc17.x86_64
Found initrd image: /boot/initramfs-3.5.2-3.fc17.x86_64.img
Found linux image: /boot/vmlinuz-3.3.4-5.fc17.x86_64
Found initrd image: /boot/initramfs-3.3.4-5.fc17.x86_64.img
done

Now reboot. The fix isn't pretty, but you can at least see all the text now.

 

Any questions, feedback, advice, complaints or meanderings are welcome.
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