On 14 November 2014 18:50, Roger Heflin <rogerheflin@xxxxxxxxx> wrote: > If you are robocoping small files you will hit other limits. > > Best I have seen with small files is around 30 files/second, and that > involves multiple copies going on. Remember with a small files there > are several reads and writes that need to be done to complete a create > of a small file and each of these take time. 30 files/second ~ 30ms > per file, not that bad considering that on a real spinning disk a > single read/write op is 5-10ms, and creating the file entry, copying > data and closing the file takes several operations (at least create > file entry, write small amount of data, update file entry > date/time/info). If the write in the middle is not a significant > amount of data, the 2 extra ops are what hurts. > But, I tried 4gb and 1gb files both got a similar numbers. > On Fri, Nov 14, 2014 at 6:55 AM, Jagan Teki <jagannadh.teki@xxxxxxxxx> wrote: >> Hi, >> >> I'm doing a performance testing on my bench ARM box. >> >> 1. dd test: I have validate the read and write by mounting /dev/sda1 >> with ext4 filesystem, >> able to get the good performance numbers where read is high >> compared to write >> >> 2. robocopy test: >> - mkfs.ext4 /dev/sda1 >> - mount /dev/sda1 /media/disk >> - << configured samba >> >> - Mapped the /media/disk on windows >> - login on the mapped driver in windows >> - did a robocopy test, where write got 84MBps and read 14MBps >> >> read performance is too slow when compared to write in robocopy case. >> Can anyone help me out, how to debug this further. thanks! -- Jagan. -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
