Hello, AA2913.
is it possible that your disks united in 2 RAID1 Arrays, so you see the logical disks not the physical disks when installing the ESXi? You can check it in your storage controller properties, for example in LSI utility for LSI Cntrollers, i guess you can reach it in UEFI, or on the stage of server starting in case of Legacy mode.
If 73gb is a nominal capactiy - you will never get the volume with same capactiy. If the storage capacity is the thing you carry about - i guess you should rebuild you disk array with the storage utility in RAID 5 for example, or RAID 0 if you not carry about the disk array failover at all.
Also you should check the compatibilty of ESXi with your disks and storage controller in VMware Compatibility Guide: System Search, but if your disks are all the same model i guess there is no need to do that.
Actually the good practice it not to run vms on the vmfs volume which is located on local disks, but i think you have no choice.
Sorry for my bad english.