On Intel-based hosts running the Linux operating system, in response to errors, the kernel might permanently disable a LUN and log a message that states both device set offline and the specific device.
The kernel typically sets a LUN offline to avoid a possible miscompare mechanism. The message is logged in the syslog, which is usually found in the /var/log/messages directory.
If you decide to remove the module or need additional details for setting the LUN online, refer to Multipath Subsystem Device Driver (SDD) documentation for more information.