Slow I/O in DS1 RRS feed

  • Question

  • From: Trung SKy @TrungSkyDz via Twitter

    I create 1 VPS choose SSD , why speed is only 15mb /s.

    i run : sync; dd if=/dev/zero of=tempfile bs=1M count=1024; sync

    very fast before the date 06.07.2016. Recent new disk slowly

    Speed I/O very slow in DS1.Why?



    Wednesday, June 15, 2016 4:41 PM

All replies

  • Hello Trung,

    Thank you for posting at Microsoft Azure Forums!

    I am not quite sure if the command "sync; dd if=/dev/zero of=tempfile bs=1M count=1024; sync" gives us the exact understanding about the speed of data transfer for your VM. There may be a number of performance bottlenecks which we would have to understand and monitor for a while at least to understand where the performance is dropping. I suggest you enable monitoring for your Linux VM and check if you can identify the cause of this issue. Please click on Generic performance troubleshooting for Azure Virtual Machine running Linux or Windows for details on how to go about enabling and reading the monitoring data for your VM.

    Also, you have mentioned "very fast before the date 06.07.2016. Recent new disk slowly". Does this mean you have added a second data disk to your VM? If so is this a premium disk or a standard disk. In either cases if you have added a additional disk then you can stripe the disks for a faster Read/Write operation which is sure to improve the performance as well. Refer to Configuring Azure Virtual Machines for Optimal Storage Performance for more details.

    Hope this helps.



    Thursday, June 16, 2016 7:30 AM