SCSI device state changes from running to offline

In some instances, the Small Computer System Interface (SCSI) mid layer changes the SCSI device state from running to offline.

I/O that is later sent to that SCSI device is rejected by the mid layer and never reaches the SCSI lower-level device drivers for processing. To solve this problem, you must increase the SCSI timeout value to at least 60 seconds as shown in the following example:
SUBSYSTEM=="scsi", ACTION=="add", ATTR{vendor}=="IBM", 
ATTR{model}==", ATTR{timeout}="60"