[orabos] A/B root partitions, Third for persistence

We could either have two completely separate paritions,
and copy things manually around, or this.
Btrfs offers the option create subvolumes for partitioning
the data further up.
Otherwise we would have to statically determine the size
of the home, var, and var/tmp partitions (or at least:
home and var).
Home should be fairly limited, so that would not be an insurmountable
problem.

As the VMs will (eventually) only run with non-local storage, the
partition will only be used for our data, which should be practically
ephemeral, and is only persisted for a faster life-cycle.

Brtfs also would offer us the option to use snapshots for rollback,
partition the paths further, or and makes it easy to add more paths,
in case of need.

features/orabos/file.exclude

@@ -1,3 +1,4 @@
 /etc/systemd/network/99-default.network
 /etc/systemd/system/systemd-resolved.service.d/wait-for-networkd.conf
+/etc/repart.d/root.conf
 /etc/kernel/cmdline.d/99-no-gpt-auto.cfg

features/orabos/file.include/etc/repart.d/root_a.conf → features/orabos/file.include/etc/repart.d/10_root_a.conf

@@ -1,2 +1,3 @@
 [Partition]
 Type=root
+SizeMaxBytes=4G

features/orabos/file.include/etc/repart.d/12_config_drive.conf

@@ -0,0 +1,7 @@
+# This needs to stay as long as we use config-drives
+# It doesn't add much in case we don't.
+# As the time of writing metal3 and nova/ironic do.
+[Partition]
+Type=linux-generic
+Label=config-2
+SizeMaxBytes=64M

features/orabos/file.include/etc/repart.d/root_b.conf → features/orabos/file.include/etc/repart.d/25_root_b.conf

@@ -1,3 +1,3 @@
 [Partition]
 Type=root
-NoAuto=on
+SizeMaxBytes=4G

features/orabos/file.include/etc/repart.d/50_persistent.conf

@@ -0,0 +1,10 @@
+[Partition]
+Type=linux-generic
+Label=persistent
+Format=btrfs
+Subvolumes=/home /srv /var /var/tmp
+CopyFiles=/home
+CopyFiles=/srv
+CopyFiles=/var
+ExcludeFiles=/var/tmp
+Weight=4000

features/orabos/file.include/etc/systemd/system/home.mount

@@ -0,0 +1,18 @@
+[Unit]
+Description=Directory (/home)
+Documentation=man:file-hierarchy(7)
+ConditionPathIsSymbolicLink=!/home
+DefaultDependencies=no
+Conflicts=umount.target
+Before=local-fs.target umount.target
+After=-.mount
+After=blockdev@dev-disk-by\x2dlabel-persistent.target
+
+[Mount]
+What=/dev/disk/by-label/persistent
+Where=/home
+Type=btrfs
+Options=subvol=/home
+
+[Install]
+WantedBy=local-fs.target

features/orabos/file.include/etc/systemd/system/local-fs.target.wants/home.mount

@@ -0,0 +1 @@
+../home.mount

features/orabos/file.include/etc/systemd/system/local-fs.target.wants/usr.mount

@@ -0,0 +1 @@
+../usr.mount

features/orabos/file.include/etc/systemd/system/local-fs.target.wants/var-tmp.mount

@@ -0,0 +1 @@
+../var-tmp.mount

features/orabos/file.include/etc/systemd/system/local-fs.target.wants/var.mount

@@ -0,0 +1 @@
+../var.mount

features/orabos/file.include/etc/systemd/system/var-tmp.mount

@@ -0,0 +1,18 @@
+[Unit]
+Description=Directory (/var/tmp)
+Documentation=man:file-hierarchy(7)
+ConditionPathIsSymbolicLink=!/var/tmp
+DefaultDependencies=no
+Conflicts=umount.target
+Before=local-fs.target umount.target
+After=var.mount
+After=blockdev@dev-disk-by\x2dlabel-persistent.target
+
+[Mount]
+What=/dev/disk/by-label/persistent
+Where=/var/tmp
+Type=btrfs
+Options=subvol=/var/tmp
+
+[Install]
+WantedBy=local-fs.target

features/orabos/file.include/etc/systemd/system/var.mount

@@ -0,0 +1,18 @@
+[Unit]
+Description=Directory (/var)
+Documentation=man:file-hierarchy(7)
+ConditionPathIsSymbolicLink=!/var
+DefaultDependencies=no
+Conflicts=umount.target
+Before=local-fs.target umount.target
+After=-.mount
+After=blockdev@dev-disk-by\x2dlabel-persistent.target
+
+[Mount]
+What=/dev/disk/by-label/persistent
+Where=/var
+Type=btrfs
+Options=subvol=/var
+
+[Install]
+WantedBy=local-fs.target