Hi,
I know FS filter driver can be used to compress/decompress data on-fly, that is, when data is read, it is decompressed automaticly, when data is written, it is compressed automaticly. The process is completely transparent to Application or User.
But if a volume filter driver or even a disk filter driver is used to compress/decompress data on-fly(data sectors compression/decompression), User or Application is still see data as no-compression state. But there is a problem: for example, if a volume is 80G, at a time, I have written 70G data in it, but through our volume filter(assume compression rate is 1:2), then actually, only 35G data is wrriten to volume. Then there is actually 45G space for free. But for User or Application, there is still only 10G(80G-70G) space for free.
Is there sth. wrong? 3ks