Research Of A Performance Optimization Me-chanism For SSD Based On Virtualization Environ-ment

In a virtualized environment, the virtual machine’s performance and efficiency cansignificantly be improved by changing the underlying storage hardware. Solid State Disk,compared with Hard Drive Disk, has a low delay, low energy consumption, high through-put, high bandwidth, and many other advantages. But it is important to note, in virtualizedenvironment we will meet challenges when use the solid state disk, because of its ownstructure and characteristics, the trim instruction that plays an important role in spacemanagement of Solid State Disk cannot be passed through a virtual machine to the under-lying Solid State Disk. So make the trim instruction be handled in virtualized environmentwill be a problem to be solved urgently.An optimized system used in virtualization environment named Vtrim can send thetrim instruction to the Solid State Disk in real time. The operating system’s deletion opera-tion can automatically trigger the trim instruction and send it to the Solid State Disk ingeneral case. Unfortunately, the deletion operation in virtual machine can not trigger thetrim instruction because of the virtualization semantic gap. To this situation, Vtrim systemmonitors the deletion operation in virtual machine and sends the deletion semantic to thedomain0immediately. Then the deletion semantic from virtual machine will be translatedto the deletion operation in domain0.This deletion operation can punch hole on virtualmachine disk image, then trigger the trim instruction. In this way, the performance of theSolid State Disk in virtualization environment will be improved.Functional test proved that Vtrim can intercept the deletion operation in virtual ma-chine and change it into deletion operation in domain0in order to trigger the trim instruc-tion in real time. Performance analysis shows that the random write performance will im-prove about150%at most in the para-virtualization virtual machine with the Vtrim. Andthe average response time will also reduce to about40%of the original one in the bestcase.