I/O errors and failure to activate logical volume or mount file system after stopping or restarting iSCSI in RHEL.

Issue

• I see I/O errors in /var/log/messages after I have stopped iSCSI:

  Jan 17 09:30:35 example kernel: scsi 1:0:0:1: rejecting I/O to dead device
  Jan 17 09:30:35 example kernel: scsi 1:0:0:0: rejecting I/O to dead device
  

• After restarting the iSCSI service, I can no longer mount the file system on my logical volume:

  # mount /dev/vg/lv /mnt/lv
  mount: wrong fs type, bad option, bad superblock on /dev/vg/lv
         missing codepage or other error
         In some cases useful info is found in syslog - try
         dmesg | tail  or so
  

• I cannot access my logical volumes properly after restarting iSCSI:

  # pvscan
    /dev/vg/lv: read failed after 0 of 4096 at 6979317596160: Input/output error
    /dev/vg/lv: read failed after 0 of 4096 at 6979317653504: Input/output error
    /dev/vg/lv: read failed after 0 of 4096 at 0: Input/output error
    /dev/vg/lv: read failed after 0 of 4096 at 4096: Input/output error
    PV /dev/sdd1   VG vg   lvm2 [5.86 TB / 0    free]
    PV /dev/sde1   VG vg   lvm2 [5.86 TB / 5.37 TB free]
    Total: 2 [11.72 TB] / in use: 2 [11.72 TB] / in no VG: 0 [0   ]
  

• After I log out of an iSCSI connection or stop the iscsi service, my device-mapper-multipath map still exists and the paths are marked as failed.