It seems that "Use existing" is not working. I have tried multiple times to redeploy the engine and it always fails . Here is the last log from vdsm : 2018-12-09 15:56:40,269+0200 INFO (JsonRpc (StompReactor)) [Broker.StompAdapter] Subscribe command received (stompreactor:132) 2018-12-09 15:56:40,310+0200 INFO (jsonrpc/1) [jsonrpc.JsonRpcServer] RPC call Host.ping2 succeeded in 0.00 seconds (__init__:573) 2018-12-09 15:56:40,317+0200 INFO (jsonrpc/7) [jsonrpc.JsonRpcServer] RPC call Host.ping2 succeeded in 0.00 seconds (__init__:573) 2018-12-09 15:56:40,321+0200 INFO (jsonrpc/4) [vdsm.api] START getStorageDomainInfo(sdUUID=u'143d800a-06e1-48b5-aa7c-21cb9f3a89a7', options=None) from=::1,4 7806, task_id=b3b5e7aa-998c-419e-9958-fe762dbf6d18 (api:46) 2018-12-09 15:56:40,321+0200 INFO (jsonrpc/4) [storage.StorageDomain] sdUUID=143d800a-06e1-48b5-aa7c-21cb9f3a89a7 (fileSD:534) 2018-12-09 15:56:40,324+0200 INFO (jsonrpc/4) [vdsm.api] FINISH getStorageDomainInfo return={'info': {'uuid': u'143d800a-06e1-48b5-aa7c-21cb9f3a89a7', 'vers ion': '4', 'role': 'Master', 'remotePath': 'ovirt1:/engine', 'type': 'GLUSTERFS', 'class': 'Data', 'pool': ['7845b386-fbb3-11e8-bfa8-00163e54fd43'], 'name': 'hosted_storage'}} from=::1,47806, task_id=b3b5e7aa-998c-419e-9958-fe762dbf6d18 (api:52) 2018-12-09 15:56:40,325+0200 INFO (jsonrpc/4) [jsonrpc.JsonRpcServer] RPC call StorageDomain.getInfo succeeded in 0.01 seconds (__init__:573) 2018-12-09 15:56:40,328+0200 INFO (jsonrpc/6) [jsonrpc.JsonRpcServer] RPC call Host.ping2 succeeded in 0.00 seconds (__init__:573) 2018-12-09 15:56:40,332+0200 INFO (jsonrpc/0) [vdsm.api] START getStorageDomainInfo(sdUUID=u'143d800a-06e1-48b5-aa7c-21cb9f3a89a7', options=None) from=::1,4 7806, task_id=19f713e3-7387-4265-a821-f636b2415f42 (api:46) 2018-12-09 15:56:40,332+0200 INFO (jsonrpc/0) [storage.StorageDomain] sdUUID=143d800a-06e1-48b5-aa7c-21cb9f3a89a7 (fileSD:534) 2018-12-09 15:56:40,336+0200 INFO (jsonrpc/0) [vdsm.api] FINISH getStorageDomainInfo return={'info': {'uuid': u'143d800a-06e1-48b5-aa7c-21cb9f3a89a7', 'vers ion': '4', 'role': 'Master', 'remotePath': 'ovirt1:/engine', 'type': 'GLUSTERFS', 'class': 'Data', 'pool': ['7845b386-fbb3-11e8-bfa8-00163e54fd43'], 'name': 'hosted_storage'}} from=::1,47806, task_id=19f713e3-7387-4265-a821-f636b2415f42 (api:52) 2018-12-09 15:56:40,337+0200 INFO (jsonrpc/0) [jsonrpc.JsonRpcServer] RPC call StorageDomain.getInfo succeeded in 0.00 seconds (__init__:573) 2018-12-09 15:56:40,341+0200 INFO (jsonrpc/5) [vdsm.api] START connectStorageServer(domType=7, spUUID=u'00000000-0000-0000-0000-000000000000', conList=[{u'i d': u'e29cf818-5ee5-46e1-85c1-8aeefa33e95d', u'vfs_type': u'glusterfs', u'mnt_options': u'backup-volfile-servers=ovirt2:glarbiter', u'connection': u'ovirt1:/ engine', u'user': u'kvm'}], options=None) from=::1,47806, task_id=2d919607-796e-4528-9f54-4dc437eddada (api:46) 2018-12-09 15:56:40,345+0200 INFO (jsonrpc/5) [vdsm.api] FINISH connectStorageServer return={'statuslist': [{'status': 0, 'id': u'e29cf818-5ee5-46e1-85c1-8a eefa33e95d'}]} from=::1,47806, task_id=2d919607-796e-4528-9f54-4dc437eddada (api:52) 2018-12-09 15:56:40,345+0200 INFO (jsonrpc/5) [jsonrpc.JsonRpcServer] RPC call StoragePool.connectStorageServer succeeded in 0.01 seconds (__init__:573) 2018-12-09 15:56:40,348+0200 INFO (jsonrpc/2) [vdsm.api] START getStorageDomainStats(sdUUID=u'143d800a-06e1-48b5-aa7c-21cb9f3a89a7', options=None) from=::1, 47806, task_id=47edd838-f7f5-448b-9b6a-a650460614ac (api:46) 2018-12-09 15:56:40,556+0200 INFO (jsonrpc/2) [storage.StorageDomain] Removing remnants of deleted images [] (fileSD:734) 2018-12-09 15:56:40,557+0200 INFO (jsonrpc/2) [vdsm.api] FINISH getStorageDomainStats return={'stats': {'mdasize': 0, 'mdathreshold': True, 'mdavalid': True , 'diskfree': '103464173568', 'disktotal': '107313364992', 'mdafree': 0}} from=::1,47806, task_id=47edd838-f7f5-448b-9b6a-a650460614ac (api:52) 2018-12-09 15:56:40,558+0200 INFO (jsonrpc/2) [jsonrpc.JsonRpcServer] RPC call StorageDomain.getStats succeeded in 0.21 seconds (__init__:573) 2018-12-09 15:56:40,564+0200 INFO (jsonrpc/3) [vdsm.api] START prepareImage(sdUUID=u'143d800a-06e1-48b5-aa7c-21cb9f3a89a7', spUUID=u'00000000-0000-0000-0000 -000000000000', imgUUID=u'dabcff49-56c0-4557-9c82-3df9e6c11991', leafUUID=u'6a4441f0-641e-49c0-a117-7913110874c6', allowIllegal=False) from=::1,47806, task_i d=edb0b0fa-d528-426e-8250-04c0f7864224 (api:46) 2018-12-09 15:56:40,584+0200 INFO (jsonrpc/3) [vdsm.api] FINISH prepareImage error=Volume does not exist: (u'6a4441f0-641e-49c0-a117-7913110874c6',) from=:: 1,47806, task_id=edb0b0fa-d528-426e-8250-04c0f7864224 (api:50) 2018-12-09 15:56:40,584+0200 ERROR (jsonrpc/3) [storage.TaskManager.Task] (Task='edb0b0fa-d528-426e-8250-04c0f7864224') Unexpected error (task:875) Traceback (most recent call last): File "/usr/lib/python2.7/site-packages/vdsm/storage/task.py", line 882, in _run return fn(*args, **kargs) File "<string>", line 2, in prepareImage File "/usr/lib/python2.7/site-packages/vdsm/common/api.py", line 48, in method ret = func(*args, **kwargs) File "/usr/lib/python2.7/site-packages/vdsm/storage/hsm.py", line 3182, in prepareImage Can someone guide me how to debug this ?