Topic
  • 5 replies
  • Latest Post - ‏2014-09-19T16:26:56Z by Mach_v
HugoD.
HugoD.
1 Post

Pinned topic V3700 slow iscsi read performance

‏2014-03-17T20:51:36Z |

Hi,

I am implementing Storwize V3700 with x3550M4, erver 2012R2 and iscsi connection. I have 2 separate NICs connected to each canister and I am using Microsoft MPIO with IBM SDDDSM for multipathing and load-balancing. The write performance seems to be okay, however the read performance is about 1/3 of write. Sequential read is about 50MB/s  Is there any known issue or performance tuning, that should be done here?

Thanks

  • Mangesh Shirke
    Mangesh Shirke
    45 Posts

    Re: V3700 slow iscsi read performance

    ‏2014-03-18T05:53:32Z  

    Hi,

    If you have large number of sequential read IOPS then there are chances of performance degradation. It again depends on configurations which you have in this storage.

    If you can share logs then we will get more idea about this issue.

    Thanks.

  • BA-SUP
    BA-SUP
    2 Posts

    Re: V3700 slow iscsi read performance

    ‏2014-09-15T08:36:32Z  

    Hi, I'm experiencing the same problem. How do you get rid of it ?

    My configuration is simple : W764b -> 1 NIC 10GB  -> V3700

    Depending of the test tool I use, results are really different.

    Best regards

  • Mach_v
    Mach_v
    16 Posts

    Re: V3700 slow iscsi read performance

    ‏2014-09-15T17:27:05Z  
    • BA-SUP
    • ‏2014-09-15T08:36:32Z

    Hi, I'm experiencing the same problem. How do you get rid of it ?

    My configuration is simple : W764b -> 1 NIC 10GB  -> V3700

    Depending of the test tool I use, results are really different.

    Best regards

    Do you set all Windows registry setting according to http://www-01.ibm.com/support/knowledgecenter/STLM5A_7.3.0/com.ibm.storwize.v3700.730.doc/svc_iscsiwindowsoptinitiator_21lgh9.html?lang=en ?

    Especially "Addressing Slow Performance with iSCSI clusters" link from here. (Disable Delayed Ack).

  • BA-SUP
    BA-SUP
    2 Posts

    Re: V3700 slow iscsi read performance

    ‏2014-09-16T05:49:17Z  
    • Mach_v
    • ‏2014-09-15T17:27:05Z

    Do you set all Windows registry setting according to http://www-01.ibm.com/support/knowledgecenter/STLM5A_7.3.0/com.ibm.storwize.v3700.730.doc/svc_iscsiwindowsoptinitiator_21lgh9.html?lang=en ?

    Especially "Addressing Slow Performance with iSCSI clusters" link from here. (Disable Delayed Ack).

    Thank you Mach for this reply.

    Unfortunately it does not really change the results. Only average transfert rate is a bit better.

    I also have the same problem if I try to initiate ISCSI in Vmware so it must not be related to Windows initiator.

    Could you please provide again the second link ?

    Best regards

  • Mach_v
    Mach_v
    16 Posts

    Re: V3700 slow iscsi read performance

    ‏2014-09-19T16:26:56Z  
    • BA-SUP
    • ‏2014-09-16T05:49:17Z

    Thank you Mach for this reply.

    Unfortunately it does not really change the results. Only average transfert rate is a bit better.

    I also have the same problem if I try to initiate ISCSI in Vmware so it must not be related to Windows initiator.

    Could you please provide again the second link ?

    Best regards

    https://www.ibm.com/developerworks/community/forums/html/topic?id=77777777-0000-0000-0000-000014955266#77777777-0000-0000-0000-000014961718