A method for preparing a storage system to execute input-output commands, IOs, issued by a virtual machine running on a host computer, the method characterised by: a storage system manager receiving a request from the host computer to prepare a metadata logical storage volume for the virtual machine, wherein the metadata logical storage volume includes configuration and log files for the virtual machine, a swap file for the virtual machine, and disk descriptor files, one for each of virtual disks of the virtual machine; in response to the request, the storage system manager creating the metadata logical storage volume for the virtual machine and returing the metadata logical storage volume ID to the host, and then receiving a binding request from the host for the metadata logical volume ID to establish an IO session, the storage system manager selecting a protocol endpoint comprising a logical endpoint for protocol traffic configured in the storage system through which IOs for the metadata logical storage volume are to be received and returning the protocol endpoint identifier and a secondary level identifier identifying the IO session; the host computer receiving read IOs through the selected protocol endpoint and returning read data, the read data including identifiers for data logical storage volumes; the storage system manager receiving a request from the host computer to prepare the data logical storage volumes for the virtual machine; the storage system manager creating a data logical storage volume for each virtual disk of the virtual machine; the storage system manager obtaining an identifier for each said data logical storage volume and transmitting the identifier to the host computer, and the host computer storing the identifier for the data logical storage volume in the disk descriptor file for the virtual disk. a storage system manager receiving a request from the host computer to prepare a metadata logical storage volume for the virtual machine, wherein the metadata logical storage volume includes configuration and log files for the virtual machine, a swap file for the virtual machine, and disk descriptor files, one for each of virtual disks of the virtual machine; in response to the request, the storage system manager creating the metadata logical storage volume for the virtual machine and returing the metadata logical storage volume ID to the host, and then receiving a binding request from the host for the metadata logical volume ID to establish an IO session, the storage system manager selecting a protocol endpoint comprising a logical endpoint for protocol traffic configured in the storage system through which IOs for the metadata logical storage volume are to be received and returning the protocol endpoint identifier and a secondary level identifier identifying the IO session; the host computer receiving read IOs through the selected protocol endpoint and returning read data, the read data including identifiers for data logical storage volumes; the storage system manager receiving a request from the host computer to prepare the data logical storage volumes for the virtual machine; the storage system manager creating a data logical storage volume for each virtual disk of the virtual machine; the storage system manager obtaining an identifier for each said data logical storage volume and transmitting the identifier to the host computer, and the host computer storing the identifier for the data logical storage volume in the disk descriptor file for the virtual disk.