FS8600 - FluidFS V5 - Speed Issues - Jumbo Frames - Compellent - Storage - Dell Community

FS8600 - FluidFS V5 - Speed Issues - Jumbo Frames

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FS8600 - FluidFS V5 - Speed Issues - Jumbo Frames

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We have had a pair of FS8600 installed with SCv2080 for the storage. This is presented on a 10Gb network for storage, we have been experiencing speed issues particularly with Read which are only ever between 85 - 105 MB/s which is slower than the old SAS storage that was being used and not much above 1Gb iSCSI. 

I have a call open with Dell who so far are stumped on a solution, we have been looking at using Jumbo Frames to increase the speeds and after testing with Dell with and without Jumbo Frames i carried out some of my own testing and found that I can successfully Ping to and from switches and workstations using a Large frame size but the FS8600 controllers will not ping with Jumbo Frames max frame size is about 1476 bytes, the FS8600 is configured with Jumbo Frames and going through SSH the ports are all configured with a large frame size.

Anyone seen or have any ideas about this as it is really getting to the point where the speed is becoming an issue and is holding up the storage going in to full production.

All Replies
  • Hi

     

    Jumbo frames should be in use on the iSCSI network between the FS8600 and the SC2080.

    For the client network itself Jumbo frames are supported and can assist in most data flows as long as all the network path is also set to Jumbo frames.

     

    In order to go forward with the performance issue you are describing please Email me (Ohad_Finkelstein@dell.com) with the case details including the Support case number and I will assist with understanding and solving this issue.

     

    Ohad Finkelstein

  • Hi,

    We have a very similar issue and it is with Read. Did you find a solution?

    Best,

    Bill

  • Hi Bill,

    We did find a resolution eventually it boiled down to a couple of things we have a mildly complicated setup with the storage 2 floors below the Fluid heads, and in order to connect the management a pair of switches were put in to be able to connect the management network, during the install the default gateway of the Fluid and the storage was configured to this switch, but this switch was not configured for Jumbo frames, we changed the default gateway to a switch that supported Jumbo frames which improved things we then also found the the subnet had been set to 255.255.255.0 during install when the network was actually a 255.255.248.0, once both these were corrected the read speeds jumped to 900MB/s

    Hope this helps,

    Neil