Linux Device-Mapper Konfiguration (mit Multipathing)
- systool (sysfsutils)
device-mapper
- device-mapper-multipath
- dmsetup message

Linux Device-Mapper Konfiguration (mit Multipathing)

systool (sysfsutils)

systool -vb scsi

Bus = "scsi"

  Device = "0:0:0:0"
  Device path = "/sys/devices/pci0000:00/0000:00:04.0/0000:03:00.0/0000:04:02.0/host0/target0:0:0/0:0:0:0"
    delete              = <store method only>
    detach_state        = "0"
    device_blocked      = "0"
    dump                = 
    model               = "SERVERAID       "
    queue_depth         = "63"
    rescan              = <store method only>
    rev                 = "1.00"
    scsi_level          = "3"
    state               = "running"
    timeout             = "30"
    type                = "0"
    vendor              = "IBM     "

  Device = "0:0:15:0"
  Device path = "/sys/devices/pci0000:00/0000:00:04.0/0000:03:00.0/0000:04:02.0/host0/target0:0:15/0:0:15:0"
    delete              = <store method only>
    detach_state        = "0"
    device_blocked      = "0"
    dump                = 
    model               = "SERVERAID       "
    queue_depth         = "3"
    rescan              = <store method only>
    rev                 = "1.00"
    scsi_level          = "3"
    state               = "running"
    timeout             = "0"
    type                = "3"
    vendor              = "IBM     "

  Device = "0:1:8:0"
  Device path = "/sys/devices/pci0000:00/0000:00:04.0/0000:03:00.0/0000:04:02.0/host0/target0:1:8/0:1:8:0"
    delete              = <store method only>
    detach_state        = "0"
    device_blocked      = "0"
    dump                = 
    model               = "25P3495a S320  1"
    queue_depth         = "3"
    rescan              = <store method only>
    rev                 = "1   "
    scsi_level          = "3"
    state               = "running"
    timeout             = "0"
    type                = "3"
    vendor              = "IBM     "

device-mapper

As this will lead to IO being queued forever, unless a path is reinstated, make sure that multipathd is running and works for your scenario. Otherwise, IO might be stalled forever on the affected MPIO device, until reboot or until you manually issue a

dmsetup message 3600601607cf30e00184589a37a31d911 0 fail_if_no_path

(substituting the correct map name), which will immediately cause all queued IO to fail. You can reactivate the queue if no path feature by issueing

dmsetup message 3600601607cf30e00184589a37a31d911 0 queue_if_no_path

You can also use these two commands to switch between both modes for testing, before committing the command to your /etc/multipath.conf.