Thanks. Still trying to think of possible workarounds for this. This is a different idea: Suppose that I re-partition the /dev/sda device into 2. (Not sure exactly how to do this yet, either via LVM or use some other utility.) And I use the first partition for real work, and the second partition for fio replay (using captures from blktrace/blkparse). Now, this would corrupt any filesystem that I have on the second partition. But would it corrupt the first partition? I would think the answer is no. Could you confirm? --- Hsiao "Shao" Su MarkLogic Senior Performance Engineer 650 287 2545 (W) -----Original Message----- From: Jens Axboe [mailto:jaxboe@xxxxxxxxxxxx] Sent: Monday, February 28, 2011 5:07 AM To: Hsiao Su Cc: fio@xxxxxxxxxxxxxxx Subject: Re: using blktrace, blkparse, and fio On 2011-02-25 13:24, Hsiao Su wrote: > > Thanks, > > A follow up question. Suppose that I use fio directly, without > blktrace and blkparse. In this case, I would have to guess the real > IO workload that my app is doing, and specify that in the job file. > Would I still have to worry about file system corruption? > > My guess is no for this one, that fio would create its own file for > replaying the workload. Depends on what the job looks like. If you stick to writing to files in a mounted fs, it'll work fine. If you tell fio to use --filename=/dev/sda or whatever the device is, you'll corrupt the file system(s) if that job file is doing writes. -- Jens Axboe -- 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
