Comment 2 for bug 1000166

The following is the description of "nova list" command in nova API, I hope this helps you to understand.

meenakshi_m@pshys0284:~$ nova help list
usage: nova list [--reservation_id <reservation_id>] [--recurse_zones [<0|1>]]
                 [--ip <ip_regexp>] [--ip6 <ip6_regexp>]
                 [--name <name_regexp>] [--instance_name <name_regexp>]
                 [--status <status>] [--flavor <flavor>] [--image <image>]
                 [--host <hostname>]

List active servers.

Optional arguments:
  --reservation_id <reservation_id>
                        Only return instances that match reservation_id.
  --recurse_zones [<0|1>]
                        Recurse through all zones if set.
  --ip <ip_regexp> Search with regular expression match by IP address
  --ip6 <ip6_regexp> Search with regular expression match by IPv6 address
  --name <name_regexp> Search with regular expression match by name
  --instance_name <name_regexp>
                        Search with regular expression match by instance name
  --status <status> Search by server status
  --flavor <flavor> Search by flavor ID
  --image <image> Search by image ID
  --host <hostname> Search instances by hostname to which they are
                        assigned