On 14 November 2014 19:22, Roger Heflin <rogerheflin@xxxxxxxxx> wrote: > What kind of underlying disk is it? GEN3 Sata link, SSD from Samsung. > > On Fri, Nov 14, 2014 at 7:36 AM, Jagan Teki <jagannadh.teki@xxxxxxxxx> wrote: >> 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. -- 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
