My setup : oVirt 4.3.1 HC on Centos 7.6, everything up2date I try to create a new iSCSI Domain. It's a new LUN/Target created on a synology bay, no CHAP (I tried with CHAP too but that does not help). I first entered the syno's address and clicked "discover" I saw the existing Targets ; I clicked the arrow on the right for LUN/Target I just created for oVirt. I then get the following Error : "Error while executing action: Failed to setup iSCSI subsystem" In hosts logs, I get : conn 0 login rejected: initiator error (02/00) Connection1:0 to [target: iqn.2000-01.com.synology:SVC-STO-FR-301.Target-2.2dfed4a32a, portal: 10.199.9.16,3260] through [iface: default] is shutdown. In engine logs, I get : 2019-03-12 14:33:35,504+01 INFO [org.ovirt.engine.core.bll.storage.connection.ConnectStorageToVdsCommand] (default task-24) [85d27833-b5d5-4bc8-b43c-88d980c30333] Running command: ConnectStorageToVdsCommand internal: false. Entities affected : ID: aaa00000-0000-0000-0000-123456789aaa Type: SystemAction group CREATE_STORAGE_DOMAIN with role type ADMIN 2019-03-12 14:33:35,511+01 INFO [org.ovirt.engine.core.vdsbroker.vdsbroker.ConnectStorageServerVDSCommand] (default task-24) [85d27833-b5d5-4bc8-b43c-88d980c30333] START, ConnectStorageServerVDSCommand(Host Name = ps-inf-int-kvm-fr-305-210.hostics.fr, StorageServerConnectionManagementVDSParameters:{hostId='6958c4f7-3716-40e4-859a-bfce2f6dbdba', storagePoolId='00000000-0000-0000-0000-000000000000', storageType=' ISCSI', connectionList='[StorageServerConnections:{id='null', connection='10.199.9.16', iqn='iqn.2000-01.com.synology:SVC-STO-FR-301.Target-2.2dfed4a32a', vfsType='null', mountOptions='null', nfsVersion='nul l', nfsRetrans='null', nfsTimeo='null', iface='null', netIfaceName='null'}]', sendNetworkEventOnFailure='true'}), log id: 7f36d8a9 2019-03-12 14:33:36,302+01 INFO [org.ovirt.engine.core.vdsbroker.vdsbroker.ConnectStorageServerVDSCommand] (default task-24) [85d27833-b5d5-4bc8-b43c-88d980c30333] FINISH, ConnectStorageServerVDSCommand, re turn: {00000000-0000-0000-0000-000000000000=465}, log id: 7f36d8a9 2019-03-12 14:33:36,310+01 ERROR [org.ovirt.engine.core.bll.storage.connection.ISCSIStorageHelper] (default task-24) [85d27833-b5d5-4bc8-b43c-88d980c30333] The connection with details '00000000-0000-0000-0000-000000000000' failed because of error code '465' and error message is: failed to setup iscsi subsystem 2019-03-12 14:33:36,315+01 ERROR [org.ovirt.engine.core.bll.storage.connection.ConnectStorageToVdsCommand] (default task-24) [85d27833-b5d5-4bc8-b43c-88d980c30333] Transaction rolled-back for command 'org.ovirt.engine.core.bll.storage.connection.ConnectStorageToVdsCommand'. 2019-03-12 14:33:36,676+01 INFO [org.ovirt.engine.core.vdsbroker.vdsbroker.GetDeviceListVDSCommand] (default task-24) [70251a16-0049-4d90-a67c-653b229f7639] START, GetDeviceListVDSCommand(HostName = ps-inf-int-kvm-fr-305-210.hostics.fr, GetDeviceListVDSCommandParameters:{hostId='6958c4f7-3716-40e4-859a-bfce2f6dbdba', storageType='ISCSI', checkStatus='false', lunIds='null'}), log id: 539fb345 2019-03-12 14:33:36,995+01 INFO [org.ovirt.engine.core.vdsbroker.vdsbroker.GetDeviceListVDSCommand] (default task-24) [70251a16-0049-4d90-a67c-653b229f7639] FINISH, GetDeviceListVDSCommand, return: [], log id: 539fb345
Similarly, I tried to deploy hosted-engine on iSCSI through cockpit (oVirt 4.3.2-rc1) Retriving the Target works, I get : The following targets have been found:  iqn.2000-01.com.synology:SVC-STO-FR-301.Target-1.2dfed4a32a, TPGT: 1 10.199.9.16:3260 fe80::211:32ff:fe6d:6ddb:3260  iqn.2000-01.com.synology:SVC-STO-FR-301.Target-2.2dfed4a32a, TPGT: 1 10.199.9.16:3260 fe80::211:32ff:fe6d:6ddb:3260 I Select the second one and then click "Next", Then I get : Retrieval of iSCSI LUNs failed. in hosts logs, I have : mars 13 09:18:22 vs-inf-int-kvm-fr-304-210.hostics.fr python[15734]: ansible-ovirt_host_storage_facts Invoked with fcp=None iscsi={'username': None, 'password': None, 'port': '3260', 'target': 'iqn.2000-01.com.synology:SVC-STO-FR-301.Target-2.2dfed4a32a', 'address': '10.199.9.16'} fetch_nested=False auth={'timeout': 0, 'url': 'https://vs-inf-int-ovt-fr-302-210.hostics.fr/ovirt-engine/api', 'insecure': True, 'kerberos': False, 'compress': True, 'headers': None, 'token': 'OhSkJagx0abRj2stqVHqyyHH6amBJTcjHQdipFTMmukXlzV-_7mavFF0XazAoSIR3-6bTa8AmDTG5NNVFiNPNw', 'ca_file': None} host=vs-inf-int-kvm-fr-304-210.hostics.fr nested_attributes=[] mars 13 09:18:23 vs-inf-int-kvm-fr-304-210.hostics.fr iscsid[4898]: Connection2:0 to [target: iqn.2000-01.com.synology:SVC-STO-FR-301.Target-2.2dfed4a32a, portal: 10.199.9.16,3260] through [iface: default] is shutdown.
Did you try to connect via iscsiadm without using oVirt? Seems like the problems is with the iSCSI storage configuration
No info provided for a few weeks, closing for now, feel free to reopen if the problem persists and the info requested can be provided.
I never succeeded to make iSCSI from the Synology work with oVirt but managed to have it worked from a centos host I do not have this setup anymore and can not test further