tests: leave an OSD node in default crush root

jewel used to create a default `rbd` pool in the default crush root
`default`, we need to have at least 1 osd to satisfy the PGs for this
created pool, otherwise the cluster will be in HEALTH_ERR state because
of `pgs stuck unclean`/`pgs stuck inactive`

Signed-off-by: Guillaume Abrioux <gabrioux@redhat.com>
(cherry picked from commit 578aa5c2d5)

tests/functional/centos/7/cluster/hosts

@@ -8,6 +8,7 @@ ceph-mgr0
 
 [osds]
 ceph-osd0 osd_crush_location="{ 'root': 'HDD', 'rack': 'mon-rackkkk', 'pod': 'monpod', 'host': 'ceph-osd0' }"
+ceph-osd1 osd_crush_location="{ 'root': 'default', 'host': 'ceph-osd1' }"
 
 [mdss]
 ceph-mds0

tests/functional/centos/7/cluster/vagrant_variables.yml

@@ -5,7 +5,7 @@ docker: false
 
 # DEFINE THE NUMBER OF VMS TO RUN
 mon_vms: 3
-osd_vms: 1
+osd_vms: 2
 mds_vms: 1
 rgw_vms: 1
 nfs_vms: 1