Comment 3 for bug 1718454

The error message is a bit misleading, there is plenty of storage available according to http://logs.openstack.org/periodic/periodic-tripleo-ci-centos-7-scenario003-multinode-oooq/5f0e976/logs/undercloud/var/log/host_info.txt.gz:

+ df -h
Filesystem Size Used Avail Use% Mounted on
/dev/xvda1 38G 3.0G 33G 9% /
devtmpfs 3.9G 0 3.9G 0% /dev
tmpfs 3.9G 148K 3.9G 1% /dev/shm
tmpfs 3.9G 428K 3.9G 1% /run
tmpfs 3.9G 0 3.9G 0% /sys/fs/cgroup
/dev/xvdd 506K 506K 0 100% /mnt/config
tmpfs 798M 0 798M 0% /run/user/1000
/dev/xvde2 72G 7.8G 60G 12% /opt

The error reported by the proxy-server propagated from the backend account-server:

Sep 19 06:46:03 centos-7-2-node-rax-dfw-10988205 account-server: 192.168.24.1 - - [19/Sep/2017:06:46:03 +0000] "HEAD /1/47/AUTH_f0d0444566d64bbc9c432f87c35bae2e" 507 - "HEAD http://192.168.24.1:8080/v1/AUTH_f0d0444566d64bbc9c432f87c35bae2e" "tx5f5cc4e06d714a658a458-0059c0bd2b" "proxy-server 1836" 0.0007 "-" 3218 -

The account-server only returns a 507 if the mount_check is set to True, which is not the case on the undercloud after puppet run. However, it is the default if the config file has not been updated by puppet yet, so I'm wondering if the config file was not synced to disk yet?