EXT2IFS performance of VHD on my Kingston UFD

This is a follow-up of article "Why VHD not working on my Kingston UFD". Originally when I used NTFS on my UFD, the performance is not satisfactory. To summarize the behavior, the "Current Disk Queue Length" is almost always above or equal to 2, never reaches 0, and the write speed is very slow.

Then, I sought for other ways. I remember there is an IFS (installable file system) driver freely available, which is written by Stephan Schreiber. Then I created an EXT2 file system on the USB flash drive. See article "Creating EXT2 USB Flash Drive from Windows".

Then I field-tested the performance of the UFD. Test 1 - file copy. Test 2 - VPC.

For Test 1, the file copy operation, it seems continuous write speed is only about 2~6MB/s (sometimes slow and sometimes fast, may be due to some non-contiguous allocation of EXT2), which is much lower than when using NTFS, which is about 10MB/s. Anyway it is still acceptable.

For Test 2, I used 7-Zip benchmark functionality from inside VPC. 7-Zip benchmark usually runs fast only with ample RAM. I intentionally let 7-Zip use more memory than the amount of RAM on the VM, and put the swap file on a VHD on the USB flash drive. I observed the behavior of disk queue length and disk write performance. The disk queue length no longer seem overwhelming, with an optimistic number of reaches to 0. To my satisfactory, the speed is really much higher than before, with highest read per minute up to 220MB/min, that is 3~4MB/s. I expect that if I allow VPC to use the disk cache, the speed can be higher, but I won't do this test for now.

See Perfmon.png for the disk queue status.