I'm having trouble to create a storage ISO Domain and attach it to a Datacenter. It just give me this error message:
Error while executing action Attach Storage Domain: Could not obtain lock
Also the oVirt's Engine log files show this error message: "setsid: failed to execute /usr/bin/ionice: Permission denied", but I was unable to identify what exactly it's trying to do to get this permission denied.
2019-11-14 16:46:07,779-03 ERROR [org.ovirt.engine.core.dal.dbbroker.auditloghandling.AuditLogDirector] (EE-ManagedThreadFactory-engine-Thread-7388) [86161370-2aaa-4eff-9aab-c184bdf5bb98] EVENT_ID: IRS_BROKER_COMMAND_FAILURE(10,803), VDSM command AttachStorageDomainVDS failed: Cannot obtain lock: u"id=e6b34c42-0ca6-41f4-be3e-3c9b2af1747b, rc=1, out=[], err=['setsid: failed to execute /usr/bin/ionice: Permission denied']"
ionice command runs in an elevated suid permissions by vdsm,
see that your host has /etc/sudoers.d/50_vdsm file with ionice command entry and that /etc/sudoers has the #includedir /etc/sudoers.d directive.