Comment 4 for bug 1588421

Or maybe not as 4.6 seems to fix that race. Though I found one change in the ALUA handler post 4.6 which modifies the handling of missing VPD identification (which leads to the "No device descriptors found" message):

commit fe8b9534a0a0356f8a76467e2c561194bdb53c84
Author: Hannes Reinecke <email address hidden>
Date: Fri May 6 10:34:35 2016 +0200

    scsi_dh_alua: do not fail for unknown VPD identification

    Not every device will return a useable VPD identification, but still
    might support ALUA. Rather than disable ALUA support we should be
    allowing the device identification to be empty and attach individual
    ALUA device handler to each devices.