Tom Lane <[EMAIL PROTECTED]> writes: > Unfortunately, I cannot believe these numbers --- the near equality of > fsync off and fsync on means there is something very wrong with the > measurements. What I suspect is that your ATA drives are doing write > caching and thus the "fsyncs" are not really waiting for I/O at all.
I wonder whether it would make sense to have an automatic test for this problem. I suspect there are lots of installations out there whose admins don't realize that their hardware is doing this to them. It shouldn't be too hard to test a few hundred or even a few thousand fsyncs and calculate the seek time. If it implies a rotational speed over 15kRPM then you know the drive is lying and the data storage is unreliable. -- greg ---------------------------(end of broadcast)--------------------------- TIP 7: don't forget to increase your free space map settings
