LVM2 bootdisk encapsulation on RHEL7/Centos7
Introduction Hi everyone, Life on overcloud nodes was simple back then and everybody loved that single 'root' partition on the (currently less than 2Tb) bootdisk. This gave us overcloud nodes partitioned like this: [root@msccld2-l-rh-cmp-12 ~]# df -h -t xfs Filesystem Size Used Avail Use% Mounted on /dev/sda2 1.1T 4.6G 1.1T 1% / The problem with this approach is that anything filling up any subdirectory on the boot disk will cause services to fail. This story is almost 30 years old. For that reason, most security policies (Think SCAP) insist that /var, /tmp, /home be different logical volumes and that any disk uses LVM2 to allow additional logical volumes. To solve this problem, whole-disk image support is coming to Ironic. It landed in 5.6.0 (See [1] ) but missed the OSP10 release. With whole-disk image support in Ironic, we could easily change overcloud-full.qcow2 to be a full-disk image with LVM and separate volumes. This work is a tremendous...