`rescan-scsi-bus.sh -r` command to remove the stale devices causing all the filesystem to go in read-only mode.

Issue

• rescan-scsi-bus.sh -r command to remove the stale devices causing all the filesystem to go in read-only mode. This could result in kernel panic for a system booting from SAN.

• Following is the result of rescan-scsi-bus.sh -r.

• With a package version lower than sg3_utils-1.28-8.el6, we see correct output:

  Scanning host 1 for  SCSI target IDs  0 1 2 3 4 5 6 7, all LUNs
  Scanning host 2 for  SCSI target IDs  0 1 2 3 4 5 6 7, all LUNs
  Scanning host 3 for  SCSI target IDs  0 1 2 3 4 5 6 7, all LUNs
   Scanning for device 3 0 0 0 ...           
  OLD: Host: scsi3 Channel: 00 Id: 00 Lun: 00
        Vendor: NECVMWar Model: VMware IDE CDR10 Rev: 1.00
        Type:   CD-ROM                           ANSI SCSI revision: 05
  0 new or changed device(s) found.          
  0 remapped or resized device(s) found.      
  0 device(s) removed.                 
  # touch file3
  # ls -l file*
  -rw-r--r--. 1 root root   61 Feb 26 23:53 file1
  -rw-r--r--. 1 root root 2062 Feb 27 00:25 file2
  -rw-r--r--. 1 root root    0 Feb 27 00:47 file3
  

• With the package version sg3_utils-1.28-9.el6_7, we see the issue occur:

  2 new or changed device(s) found.              ANSI SCSI revision: 05
  NEW:    [0:0:0:0]
          [0:0:1:0]
  0 remapped or resized device(s) found.      
  3 device(s) removed.                 
          [0:0:0:0]
          [0:0:1:0]
          [3:0:0:0]
  # touch file4
  touch: cannot touch `file4': Read-only file system