Configure grub to default to the right kernel, not the greatest installed one.
Configure grub to default to the right kernel, not the greatest installed one.

This is sticky; that is, even if you install other kernels (manually/via fab/etc),
grub will keep booting up the one that was last enabled via teuthology config.
Use teuthology to switch kernels and it'll just work.

If the kernel the grub default points to is removed, grub will fall back to
booting the kernel with the greatest version number.

Closes: http://tracker.newdream.net/issues/1364

SUSE/teuthology,ceph/teuthology,zhouyuan/teuthology,ivotron/teuthology,dmick/teuthology,robbat2/teuthology,robbat2/teuthology,ktdreyer/teuthology,dmick/teuthology,dreamhost/teuthology,michaelsevilla/teuthology,ktdreyer/teuthology,SUSE/teuthology,tchaikov/teuthology,caibo2014/teuthology,yghannam/teuthology,t-miyamae/teuthology,SUSE/teuthology,tchaikov/teuthology,dreamhost/teuthology,yghannam/teuthology,ceph/teuthology,caibo2014/teuthology,ivotron/teuthology,dmick/teuthology,zhouyuan/teuthology,michaelsevilla/teuthology,t-miyamae/teuthology