Hi, I'm trying to use these 3 tools to capture the IO workload of an application. This application uses several different IO libraries. However, I'm not sure if I'm doing this right, so I've been trying to do this on a much smaller scale. For this small scale test, my workload is simply to use the cp command to copy a large file onto the same filesystem, then use blktrace/blkparse/fio to replay that. Some questions: 1) Is using blkparse necessary? I've actually found that you can skip blkparse, and simply use the output of blktrace and input it into fio. The result is that the replay is much much longer. My cp command took only 1.5 minutes, but if I skip blkparse, the replay via fio would take almost an hour. 2) Because of #1, I suspect that blkparse is a must. So I've included the blkparse step. But when I replay it via fio on the same device, it took about 4-5 minutes. Does this sound about right? Should I expect the fio replay to be 3-4 times longer than the original workload? I was expecting that their time should be the same. 3) I'm seeing so possible file system corruption now. When I remove a file, I get an Input/Output Error. Is this possibly due to what I had done in #1 and #2? In general, when using fio, what steps should I take to prevent a file system corruption? --- Hsiao "Shao" Su MarkLogic Senior Performance Engineer 650 287 2545 (W) -- To unsubscribe from this list: send the line "unsubscribe fio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
