Running the ioscan Command on an HP-UX hpv2 Host After Deleting All LUN Mappings Took Three Minutes to Return Results

Publication Date:  2012-07-19 Views:  155 Downloads:  0
Issue Description

Product and version information:

  • S5500T V100R001 V100R002
  • S5600T V100R001 V100R002
  • S5800T V100R001 V100R002
  • S6800T V100R001 V100R002
  • Application server operating system:
    HP-UX hpv2 B.11.23 U ia64 0901983900 unlimited-user license
  • HBA:
    HP AB379-60001 4Gb Dual Port PCI/PCI-X Fibre Channel Adapter
  • Driver:
    libfcd.a HP Fibre Channel ISP 23xx & 24xx Driver B.11.23.08.02

1.The host and the storage array were properly connected.
2.Log in to the storage array management system. Create LUNs and map them to the host. Log in to the host. All mapped LUNs were discovered.
3.Log in to the storage array management system. Remove all LUN mappings. Run the ioscan command on the host. The result was returned after about 3 minutes and 10 seconds.

Alarm Information
None
Handling Process
1.Do not delete all LUN mappings from an HP_UX hpv2 host. Replace one by one if you want to change LUN mappings.
2.If you have already deleted all LUN mappings and have run the ioscan command, wait three minutes for the ioscan command to time out.
Root Cause
.After we ran the ioscan command, the storage array log displayed "Parameter in CDB invalid, Alloc Len 8 < 16".
According to the SPC-4 R19 protocol, ALLOCATION LENGTH must be larger than 16. Figure1 and Figure2 show the related description in the SPC-4 R19 protocol.
Figure 1 Related description in the SPC-4 R19 protocol

 
Figure 2 Related description in the SPC-4 R19 protocol

 
 
2.Therefore, the problem was due to a format error in the CDB sent by the HBA. After the storage array reported the error, the host continuously sent incorrect read commands. The problem was caused by an HBA issue.
Suggestions
1.Do not delete all LUN mappings for a host.
2.Replace one by one if you want to change LUN mappings.
3.This case applies only to HP_UX hpv2 hosts.

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