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"