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IJ40280: CHECKSUM ERROR ON NETWORK I/O

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APAR status

  • Closed as program error.

Error description

  • NSD checksum errors are encountered in a cluster with
verbsRdmaSend enabled, similar to:

2021-09-27_15:46:52.820+0200: [W] Encountered first
checksum error on network I/O to NSD Server disk RG002
2021-09-27_15:46:52.820+0200: [W] Encountered first
checksum error on network I/O from NSD Client
10.124.70.48 (node1)
2021-09-27_15:46:53.655+0200: [W] Encountered first
checksum error on network I/O from NSD Client
10.124.70.55 (node2)
2021-10-01_12:47:35.002+0200: [W] Encountered first
checksum error on network I/O from NSD Client
10.124.70.45 (node3)
2021-10-01_13:11:18.187+0200: [W] Encountered first
checksum error on network I/O to NSD Server disk RG002
2021-10-01_13:11:18.211+0200: [W] Encountered first
checksum error on network I/O to NSD Server disk RG003

There is a timing window where the data has arrived on
the RDMA adapter on the GPFS client, and the client
accesses the file data in the pagepool before the data
has been copied to pagepool.

LOCAL FIX:

Local fix

  • 



Problem summary


    

  • Potential for data integrity issues on all clusters using RDMA

    



Problem conclusion


    

  • This problem is fixed in 5.1.2 PTF 5
To see all Spectrum Scale APARs and
their respective fix solutions refer to page
https://public.dhe.ibm.com/storage/spectrumscale/spectrum_scale_
apars.html

Benefits of the solution:

Fixed code so that the integrity issue can no longer happen.

Work around:
Disable RDMA or set nsdCksumTraditional
configuration parameter to "yes".
Problem trigger:
Race condition between the RDMA software layer
and IBM Spectrum Scale when reading data.
Symptom:
Unexpected Results/Behavior
Platforms affected:
ALL Linux OS environments
Functional Area affected:
RDMA
Customer Impact:
Critical

    



Temporary fix


    

  • 



Comments


    

  • 



APAR Information




    

  • APAR number
    IJ40280
    • 

  • Reported component name
    SPEC SCALE DME
    • 

  • Reported component ID
    5737F34AP
    • 

  • Reported release
    512
    • 

  • Status
    CLOSED  PER
    • 

  • PE
    NoPE
    • 

  • HIPER
    NoHIPER
    • 

  • Special Attention
    NoSpecatt / Xsystem
    • 

  • Submitted date
    2022-05-25
    • 

  • Closed date
    2022-07-20
    • 

  • Last modified date
    2022-09-08
    • 





    

  • APAR is sysrouted FROM one or more of the following:
    

    • 

  • APAR is sysrouted TO one or more of the following:
    

    • 



Fix information


    

  • Fixed component name
    SPEC SCALE DME
    • 

  • Fixed component ID
    5737F34AP
    • 



Applicable component levels


    








      
              
                            

              

              [{"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Product":{"code":"STXKQY"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"512","Line of Business":{"code":"LOB26","label":"Storage"}}]
              

                                                                    

          
 
        

      

    

      

        

          

            
Document Information


            

            


                        

            Modified date:
            

            08 September 2022
            

            
                      

        


        

        


      

    

  



    

  

  
    
            

          
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