geo-rep/gverify: Never use ping to check for host reachability

On many linux distributions with iptables enabled, ICMP traffic
is usually dropped even when port 22 is open for SSH service

So practically `ping` is an unreliable command

~~~
root@rhs1:/var/log/glusterfs # gluster volume geo-replication geo-test \
                          17.16.10.1::geo-test-slave create push-pem force
172.16.10.1 not reachable.
geo-replication command failed
~~~

~~~
root@rhs1:/var/log/glusterfs # ping 172.16.10.1
PING rhs2.sjc.redhat.com (172.16.10.1) 56(84) bytes of data.
From rhs2.sjc.redhat.com (172.16.10.1) icmp_seq=1 Destination Host Prohibited
...
...
~~~

~~~
root@rhs2:/var/log/glusterfs # service iptables status | grep 22
4    ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0           tcp dpt:22
root@rhs2:/var/log/glusterfs # service iptables status | grep icmp-host-prohibited
25   REJECT     all  --  0.0.0.0/0            0.0.0.0/0           reject-with icmp-host-prohibited
~~~

Change-Id: I33206ca071aa5d755c0762f7c486da222ec3c7db
BUG: 1105337
Signed-off-by: Harshavardhana <harsha@harshavardhana.net>
Reviewed-on: http://review.gluster.org/7997
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Aravinda VK <avishwan@redhat.com>
Reviewed-by: Venky Shankar <vshankar@redhat.com>
Tested-by: Venky Shankar <vshankar@redhat.com>

0 files changed, 0 insertions, 0 deletions