diskinfo hit "I/O error" while opening the device

[Jian-ping Hui]

On HP-UX 11.31, we are using Persistent DSF for test. We have two machines which share 1 LUN "/dev/rdisk/disk11". There are couples of partitions "/dev/rdisk/disk11_p1 ~ /dev/rdisk/disk11_p13" on this LUN.
On the first node, we reserved a shared LUN by the SCSI-3 PGR command "PERSISTENT OUT". The reservation type is "Exclusive write access for registrants". On the other node, we hit a very strange behavior while running diskinfo to check the LUN:
1. diskinfo ran well on the LUN
# diskinfo /dev/rdisk/disk11
SCSI describe of /dev/rdisk/disk11:
vendor: HITACHI
product id: DF600F
type: direct access
size: 0 Kbytes
bytes per sector: 0
2. diskinfo failed to open the device on the LUN's partitions
# diskinfo /dev/rdisk/disk11_p3
diskinfo: can't open /dev/rdisk/disk11_p3: I/O error

This confused us. We have no idea what difference while opening the LUN and the LUN's partitions.

Also, we can always see the Unit Attention 0x2a00(PARAMETERS CHANGED) while issuing some IOCTL commands on the LUN. Does this mean there are other processes working on this LUN?

Could anybody please give some help on this? Appreciate for your helps in advance.

[Santhosh D]

This is a possible issue with the SCSI Cable or its termination.

Check the SCSI Cable or try with a Different SCSI Cable.

Also Terminator.