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issues iowait

jazz1611jazz1611 Member
edited October 2014 in Help

Hi,

Im running server Dual L5520, 4x2TB SATA3 LSI-9260-8i (without BBU). i have issues with iowait high load. im running 6 windows VM with jingling. 2 core, 4gb ram for VM each.

on iotop



on top -c

Comments

  • drserverdrserver Member, Host Rep

    said: im running 6 windows VM with jingling

    here is what is the problem

    Thanked by 3jazz1611 ATHK lukesUbuntu
  • ndelaespadandelaespada Member, Host Rep

    correct, Jingling kills io

    Thanked by 1jazz1611
  • jazz1611jazz1611 Member

    @drserver: possible or issues from LSI or anything. Current BBU is died then cache not enabled.

  • MarkTurnerMarkTurner Member

    Not having the BBU is going to disable your write cache.

    I am not sure if LSI give any tools to show actual IO stats but if they do what does that show?

  • jazz1611jazz1611 Member
    edited October 2014

    still finding issues

  • drserverdrserver Member, Host Rep

    Just for the record. Make ramdisk where windows will swap and where ie will dump tmp and you will not see any of those.

  • TheLinuxBugTheLinuxBug Member

    @jazz1611 Why did you open a thread here if you were not going to let us know the resolution or keep the topic open for conversation? This is not your help desk!

    If you are not going to open threads for actual conversation and only for your own help use, then don't open threads here, please. It a huge waste to open a thread to only close it without even discussing your resolution. Makes a bunch of useless threads that clutter the board this way.

    Cheers!

  • jazz1611jazz1611 Member
    edited October 2014

    i have do follow this: https://www.binarylane.com.au/support/articles/1000055889-how-to-benchmark-disk-i-o

    and there is result of Random read/write performance

    Random read performance

  • wychwych Member

    Jingling kills disk I/O buddy.

  • jazz1611jazz1611 Member

    @wych i test disk io without VM run. check performance first.

  • AnthonySmithAnthonySmith Member, Patron Provider

    jazz1611 said: @wych i test disk io without VM run. check performance first.

    and then when you run the vm's you get high iowait, looks like you have your answer :)

  • wychwych Member

    @jazz1611 said:
    wych i test disk io without VM run. check performance first.

    As @drserver advised I would try a RAMdisk.

    @AnthonySmith said:
    and then when you run the vm's you get high iowait, looks like you have your answer :)

    Yep, no magic cure.

  • drserverdrserver Member, Host Rep

    Jingling is specific crappy app which is doing lots of really small writes. Which leads disk to get crazy. Now if you ask me Jingling without raid 10 ssd is not an option.

    You can sacrifice ram to enable windows ramdisk however best bet is ssd, as much as you can ssds.

    Now you can see from first hand why most of providers don't like Jingling

  • jazz1611jazz1611 Member
    edited October 2014

    OVH: 3x2TB SATA3 LSI-9271-4i 1GB Cached. I/O: 660MB/s on VM

    >

    Serverdeals: 4x2TB SATA3 LSI-9260-8i 512MB Cached. I/O: 260MB/s on VM

    Why that? Raid10 low performance more Raid5. All node just running one VM.

  • WilliamWilliam Member

    hm? Did you even read the output? The first result is clearly cached (3 HDDs CANNOT do more than 400MB/s), the second is real and a good result.

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