Design And Implemention Of Software Intermediate Layer

With the information growth and the disk drive progress of technology of theory,disk records have maintained density about30%annual growth rate. Because theinfluence of paramagnetic limit, it is difficult to further improve the density disk records,for the limitation of the vertical magnetic recording. In order to overcome or alleviate theimpact of paramagnetic limit, and to further improve the disk records density, a lot of newacademic magnetic recording technology is put forward.TDMR have combined into the SWR with TDMR, which benefit the recordingdensity more than5TB/in2. Compared with other technology, the technology can recordin the existing recording medium and the current magnetic head technology, which hasbeen extensive concern; it can increase the density of the record to10TB/in2on the recordstorage technology of high density in the feasibility study. However, technology andtraditional technology record reading and writing character is different, reading andwriting data will have the problems of data interference, which writing data cannot bedirectly updated, so writing performance is difficult to meet the traditional diskperformance.Through the analysis of Trace of reading and writing, most of the data will notchange in a day, influenced space also very small, so we can use a piece of random accessstorage area to server random access, and then write back to the whole if it is needed.Software interface layer model has been introduced to avoid that the shingledrecording can not update-to-date, it transparently supports a variety of general file system,at the same time the average performance of reading and writing average is25%of thetraditional disk, continuous IO request shows good performance compapare to the randomIO request, while is has little affect in Band.