Recent proposals of emerging data storage devices make it necessary to reevaluate all levels of the storage hierarchy to optimize the software stack performance.However,these new devices are not always widely availabl...Recent proposals of emerging data storage devices make it necessary to reevaluate all levels of the storage hierarchy to optimize the software stack performance.However,these new devices are not always widely available and therefore early experiments may be impossible.Emulators aim at mimicking as close as possible the behavior of a component,nonetheless,emulating new and fast storage devices is a challenging task due to time perception.In this work,we propose an approach to emulate storage devices using virtual machines(VMs)allowing the evaluation of a new device within a real system.We use a technique called freezing time,which pauses a VM to manipulate its clock and hide the real I/O completion time.Our approach is implemented at the hypervisor level and it is transparent to the vip operating system or application.We evaluate the technique under a real system using regular magnetic disks to emulate faster storage devices.Our method presented a latency error of 6.5%compared to a real device.Moreover,decoupled experiment between two laboratories,at the Barcelona Super Computing Center(BSC)in Spain,and the Center of Computer Science and Free Software(C3SL)in Brazil,demonstrated that our approach is reproducible and promising to allow the virtual evaluation of next-gen storage devices.展开更多
基金supported by the Spanish Ministry of Science and Innovation under the TIN2015-65316 Grantthe Generalitat de Catalunya under contract 2014-SGR-1051+1 种基金the Serrapilheira Institute(Grant number Serra-1709-16621)as well as the European Union’s Horizon 2020 Research and Innovation Programme,under Grant Agreement no.671951(NEXTGenIO)for the extensions added after the MASCOTS paper.
文摘Recent proposals of emerging data storage devices make it necessary to reevaluate all levels of the storage hierarchy to optimize the software stack performance.However,these new devices are not always widely available and therefore early experiments may be impossible.Emulators aim at mimicking as close as possible the behavior of a component,nonetheless,emulating new and fast storage devices is a challenging task due to time perception.In this work,we propose an approach to emulate storage devices using virtual machines(VMs)allowing the evaluation of a new device within a real system.We use a technique called freezing time,which pauses a VM to manipulate its clock and hide the real I/O completion time.Our approach is implemented at the hypervisor level and it is transparent to the vip operating system or application.We evaluate the technique under a real system using regular magnetic disks to emulate faster storage devices.Our method presented a latency error of 6.5%compared to a real device.Moreover,decoupled experiment between two laboratories,at the Barcelona Super Computing Center(BSC)in Spain,and the Center of Computer Science and Free Software(C3SL)in Brazil,demonstrated that our approach is reproducible and promising to allow the virtual evaluation of next-gen storage devices.
