Arvados

Running on a test environment, I run this command three times

HOSTNAME="shell.y5x3o.local" 

arv --format=uuid virtual_machine create --virtual-machine "{\"hostname\":\"${HOSTNAME}\"}")

All the times, the command was successful, but now I have three different entries for the same hostname in the arvados database:

arv --format=uuid virtual_machine list --filters '[["hostname", "=", "shell.y5x3o.local"]]'
y5x3o-2x53u-wdku3rjrc5oeu69
y5x3o-2x53u-zzaaiyum3hi0u66
y5x3o-2x53u-m9edn674g0lp572

and

arv virtual_machine list --filters '[["hostname", "=", "shell.y5x3o.local"]]'

{
 "kind":"arvados#virtualMachineList",
 "etag":"",
 "self_link":"",
 "offset":0,
 "limit":100,
 "items":[
  {
   "href":"/virtual_machines/y5x3o-2x53u-wdku3rjrc5oeu69",
   "kind":"arvados#virtualMachine",
   "etag":"1unl0w6q8ve8ng6qvug383i5g",
   "uuid":"y5x3o-2x53u-wdku3rjrc5oeu69",
   "owner_uuid":"y5x3o-tpzed-000000000000000",
   "created_at":"2016-11-04T20:59:45.911428000Z",
   "modified_by_client_uuid":"y5x3o-ozdt8-l7cuuwe5psnw6rd",
   "modified_by_user_uuid":"y5x3o-tpzed-000000000000000",
   "modified_at":"2016-11-04T20:59:45.910968000Z",
   "hostname":"shell.y5x3o.local" 
  },
  {
   "href":"/virtual_machines/y5x3o-2x53u-zzaaiyum3hi0u66",
   "kind":"arvados#virtualMachine",
   "etag":"38rwb00vvtueabygkmmelqe58",
   "uuid":"y5x3o-2x53u-zzaaiyum3hi0u66",
   "owner_uuid":"y5x3o-tpzed-000000000000000",
   "created_at":"2016-11-04T18:41:42.009550000Z",
   "modified_by_client_uuid":"y5x3o-ozdt8-l7cuuwe5psnw6rd",
   "modified_by_user_uuid":"y5x3o-tpzed-000000000000000",
   "modified_at":"2016-11-04T18:41:42.009076000Z",
   "hostname":"shell.y5x3o.local" 
  },
  {
   "href":"/virtual_machines/y5x3o-2x53u-m9edn674g0lp572",
   "kind":"arvados#virtualMachine",
   "etag":"8dszolebiunm71sducp8vsedq",
   "uuid":"y5x3o-2x53u-m9edn674g0lp572",
   "owner_uuid":"y5x3o-tpzed-000000000000000",
   "created_at":"2016-11-04T16:39:02.681695000Z",
   "modified_by_client_uuid":"y5x3o-ozdt8-l7cuuwe5psnw6rd",
   "modified_by_user_uuid":"y5x3o-tpzed-000000000000000",
   "modified_at":"2016-11-04T16:39:02.680712000Z",
   "hostname":"shell.y5x3o.local" 
  }
 ],
 "items_available":3
}