Earlier you mentioned that there's no ISO mounted. However the log file shows
Mar 05 09:15:49.919: vmx| DICT ide1:0.fileName = /vmfs/volumes/80eb1d95-4024e007/ISOs/ISO/OracleLinux-R5-U7-Server-x86_64-dvd.isoPlease edit the VM's settings and set the CD-ROM to e.g. "Client Device" and disconnect it to see whether this removed Datastore01 from the list of in-use datastores.
André