Advanced Power Management on WD20EZRX-00D8PB0

Hello,

I have a NAS, and i want to activate ‘standByMode’ on my WDC WD20EZRX-00D8PB0.
But I can’t. I see that Advanced Power Management is set to NO.

So my question is : how to set it to yes, as i can stand by my HDD
Another question is why i get the hdparm: ioctl 0x304 failed: Inappropriate ioctl for device
Thank you

hdparm -i /dev/sdb

/dev/sdb:
hdparm: ioctl 0x304 failed: Inappropriate ioctl for device

 Model=WDC WD20EZRX-00D8PB0                    , FwRev=80.00A80, SerialNo=     WD-WCC4N6ZT2CKL
 Config={ HardSect NotMFM HdSw>15uSec SpinMotCtl Fixed DTR>5Mbs FmtGapReq }
 RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=0
 BuffType=(0) unknown, BuffSize=0kB, MaxMultSect=16, MultSect=?0?
 CurCHS=16383/16/63, CurSects=16514064, LBA=yes, LBAsects=268435455
 IORDY=on/off, tPIO={min:120,w/IORDY:120}, tDMA={min:120,rec:120}
 PIO modes:  pio0 pio3 pio4
 DMA modes:  mdma0 mdma1 mdma2
 UDMA modes: udma0 udma1 udma2
 AdvancedPM=no WriteCache=enabled
 Drive conforms to: Unspecified:  ATA/ATAPI-1 ATA/ATAPI-2 ATA/ATAPI-3 ATA/ATAPI-4 ATA/ATAPI-5 ATA/ATAPI-6 ATA/ATAPI-7 ATA/ATAPI-8 ATA/ATAPI-9

 * current active mode