k8s pod挂载pvc，pvc通过pv连接了glusterfs。 pod一直处于creating状态，kubectl descibe pod 显示如下错误：
Mounting command: systemd-run Mounting arguments: --description=Kubernetes transient mount for /var/lib/kubelet/pods/6e95525e-63ea-11e8-9cf1-5254000c4f61/volumes/kubernetes.io~glusterfs/tfworkflow-glusterfs-pv --scope -- mount -t glusterfs -o log-level=ERROR,log-file=/var/lib/kubelet/plugins/kubernetes.io/glusterfs/tfworkflow-glusterfs-pv/busybox-q46jq-glusterfs.log,backup-volfile-servers=172.16.1.1 172.16.1.1:gv-test /var/lib/kubelet/pods/6e95525e-63ea-11e8-9cf1-5254000c4f61/volumes/kubernetes.io~glusterfs/tfworkflow-glusterfs-pv Output: Running scope as unit run-22169.scope. Mount failed. Please check the log file for more details. the following error information was pulled from the glusterfs log to help diagnose this issue: [2018-05-30 09:19:09.574623] I [fuse-bridge.c:5834:fini] 0-fuse: Unmounting '/var/lib/kubelet/pods/6e95525e-63ea-11e8-9cf1-5254000c4f61/volumes/kubernetes.io~glusterfs/tfworkflow-glusterfs-pv'. [2018-05-30 09:19:09.574633] I [fuse-bridge.c:5839:fini] 0-fuse: Closing fuse connection to '/var/lib/kubelet/pods/6e95525e-63ea-11e8-9cf1-5254000c4f61/volumes/kubernetes.io~glusterfs/tfworkflow-glusterfs-pv'. Warning FailedMount 30m kubelet, st3-aknode-28.prod.yiran.com MountVolume.SetUp failed for volume "tfworkflow-glusterfs-pv" : mount failed: mount failed: exit status 1
注：pod在机器node-2（172.16.1.2）上。
查看日志文件/var/lib/kubelet/plugins/kubernetes.io/glusterfs/tfworkflow-glusterfs-pv/busybox-q46jq-glusterfs.log中有如下报错：
[2018-05-30 09:18:36.778752] I [MSGID: 101190] [event-epoll.c:602:event_dispatch_epoll_worker] 0-epoll: Started thread with index 2 [2018-05-30 09:18:36.778845] W [MSGID: 101174] [graph.c:360:_log_if_unknown_option] 0-gv0-readdir-ahead: option 'parallel-readdir' is not recognized [2018-05-30 09:18:36.778908] W [MSGID: 101174] [graph.c:360:_log_if_unknown_option] 0-gv0-client-0: option 'transport.socket.keepalive-count' is not recognized [2018-05-30 09:18:36.778928] I [MSGID: 114020] [client.c:2356:notify] 0-gv0-client-0: parent translators are ready, attempting connect on transport [2018-05-30 09:18:36.780784] E [MSGID: 101075] [common-utils.c:314:gf_resolve_ip6] 0-resolver: getaddrinfo failed (Name or service not known) [2018-05-30 09:18:36.780795] E [name.c:262:af_inet_client_get_remote_sockaddr] 0-gv0-client-0: DNS resolution failed on host node-1
注： glusterfs在机器node-1（172.16.1.1）上。
找到Name or service not known错误， 就容易排查了。
原因是： 在机器node-2（172.16.1.2）上ping 172.16.1.1可以， 但是ping node-1是不通的。