Why dmesg is showing write through when the disk connected to Adaptec AAC-RAID is set to write-back as per Adaptec Storage Manager?

Issue

Why dmesg is showing write through when the disk connected to Adaptec AAC-RAID is set to write back as per Adaptec Storage Manager?

dmesg command is showing following output.

  Vendor: Adaptec   Model: Data              Rev: V1.0
  Type:   Direct-Access                      ANSI SCSI revision: 02
sdb : very big device. try to use READ CAPACITY(16).
SCSI device sdb: 9762222080 512-byte hdwr sectors (4998258 MB)
sdb: Write Protect is off
sdb: Mode Sense: 06 00 10 00
SCSI device sdb: drive cache: write through w/ FUA
sdb : very big device. try to use READ CAPACITY(16).
SCSI device sdb: 9762222080 512-byte hdwr sectors (4998258 MB)
sdb: Write Protect is off
sdb: Mode Sense: 06 00 10 00
SCSI device sdb: drive cache: write through w/ FUA
sdb: sdb1
sd 0:0:1:0: Attached scsi removable disk sdb