Rebuilding the initramfs on oVirt Node

Elephants being
unloaded {width=”640” height=”510”}

If you are using oVirt Node with multipath storage, then you might have noticed that there are some oddities around this. Mainly that using multipath hardware for booting Node (i.e. when you install Node on an iSCSI or FC target), will not utilize all paths.

There are two main reasons for this:

The persistence does not work very well in the very-early boot process
The initramfs has no host specific configuration

The (second issue will be addressed in oVirt 3.6](https://bugzilla.redhat.com/show_bug.cgi?id=1235965) and hopefully resolves most of the issues around multipath.

Bit even in oVirt 3.5 you can alrady try to regenerate the initramfs to address those issues. How? Just follow the small steps below after dropping to a shell from the setup TUI using F2:

WARNING: This will overvwrite your existing initrd image. Take additional steps to backup it as needed. In the worst case you are left with an unbootable system.

# Do your changes to /etc/multipath.conf
# And persist it: persist /etc/multipath.conf

# Now: Generate the new initrd
dracut /var/tmp/initrd0.img

# If that passed, let's install it:
# Let's mount /boot
/usr/libexec/ovirt-functions mount_liveos
mount -oremount,rw /liveos
mount -obind /liveos /boot

cp /var/tmp/initrd0.img /boot/initrd0.img

reboot

The reboot should boot the new initrd.

Let me know if this is working with or without problems.

::: {#footer} [ September 29th, 2015 10:17am ]{#timestamp} [ovirt]{.tag} [node]{.tag} [dracut]{.tag} [multipath]{.tag} [persistence]{.tag} [fedora]{.tag} :::