Rescan SCSI bus in Linux

When working with SCSI-, SAS- and FC- devices the need to advertise new devices to a running system will arise earlier or later.

All needed nodes are provided in /sys filesystem.

To find out which adapter is installed the following simple command is sufficient:

# cat /sys/class/scsi_host/host5/modeldesc

The answer describes the used adapter in clear:

Emulex LPe1150 4Gb PCIe Fibre Channel Adapter LP

If the controller is a pure SCSI / SAS controller just issue the following command:

echo "- - -" > /sys/class/scsi_host/host6/scan

If the device is a Fibrechannel device it is necessary to first issue a so called "Fibre Channel Loop Initialization Primitive "LIP".

echo 1 > /sys/class/fc_host/host6/issue_lip

After waiting about 15 seconds the real scan can be started

echo "- - -" > /sys/class/scsi_host/host6/scan

Finally "dmesg" can be used to check for success. The new devices should be listed there.