2 Replies Latest reply on Apr 14, 2011 1:11 PM by hmadsen

    Really weird raid problem




      I have a server SR1530HSH and in the PCI-e slot i have a Intel SRCSATAWB Raid card.


      The server chassis have 3 hotswap docking stations for easy access to change the discs..


      The Raid consists of 3 1TB Seagate drives.


      The raid was performing poorly (about 35Mbyte read and 10Mbyte write) so i wanted to take the discs out one by one and test them elsewhere (While replacing the missing drive with a spare drive of the same make and size).


      Only problem was that whenever i tried to make the raid rebuild itself i would get a warning that it failed because the drive was bad....


      Sooo, i began investigating and i can conclude that if i take the raid backplane out of the server and place it on top of the server and attach the discs i get 200Mbyte read speed and 110Mbyte write speed.


      But whenever i put the backplane back into the server i get poor performance.


      The server sees all three drives and is working even when the backplane is in the server, it just performs really poor..


      My next move would be to give the backplane a thorough inspection and possibly a resoldering of any suspected bad solderings but it seems strange if it is bad connections when the drives can be detected by the computer.


      I have confirmed the in / out performance of the backplane by taking it out and reinstalling it a total of 3 times and every time it is in it performs badly and every time it is out it performs ok..


      Am i the first to have this problem ?



        • 1. Re: Really weird raid problem

          Most likely it's caused by vibration. SATA drives are very sensitive to vibration. In some case, vibration may cause 90% performance degrade, and even drive offline. In a 1U chassis, high speed fans may generate chassis vibration. That's why enterprise SATA HDDs are always recommended, which have better tolerance of vibration. I'd highly recommend you chose HDDs from the Tested hardware list.

          • 2. Re: Really weird raid problem

            Hi Edward


            You are absolutely right.


            After some extensive testing i found that the 2 fans was generating the problem and that it was not an electrical problem.


            Logged in here to share my findings as your reply was not here last time i checked the thread.


            The problem got so bad that when i did testing with the fans on and off i took one fan off while testing and the raid dropped a drive from the raid and i am currently rebuilding.


            My budget does not allow me to change the discs right now so i will have to find some way of dampening the fans so the vibrations from them does not reach the chassis and also do some dampening on the drive bays if at all possible.


            Have marked your answer as the right one ... Thanks a bunch for your help...