The “rescan-scsi-bus.sh” can be used to scan new LUNs in a CentOS/RHEL machine.

When ‘rescan-scsi-bus.sh -i’ is run, script execute as well a LIP_RESET (ISSUE_LIP) which may cause a disruption in I/O on the server and even cause an outage in case of a system running on heavy load.

Redhat says this type of scan can be distributive,since it can cause delays while I/O operation timeout and remove devices unexpectedly from OS.

So perform this scan when really you want to scan the disks and LUNS.

The easy way to use “sg3_utils”.

Make sure you have already installed the “sg3_utils” package to use this script. Otherwise, run the following command to install it.

As a root user:

  • For RHEL/CentOS 6/7 systems, use the yum command:

yum install -y sg3_utils

  • For RHEL/CentOS 8 and Fedora systems, use the dnf command :

dnf install -y sg3_utils

  • Now you can rescan the LUNs using the rescan-scsi-bus.sh script.

./rescan-scsi-bus.sh

Thats it.