Linux on Z also supports less expensive disk storage devices than z/OS because Linux does not require FICON or ESCON attachment, although z/OS may use disk space more efficiently, on balance, due to hardware-assisted database compression common on z/OS and the smaller number of operating system instances z/OS typically requires. There are also some operational advantages using some FICON-attached storage with Linux on Z, for example support for z/VM Live Guest Relocation.