Disk spins down too fast

edit

I am trying to set the spin down timer of a harddisk to 30min. The disk is a Seagate IronWolf NAS with 4TB. I tried this command so far:

[root@localhost ~]# hdparm -B 127 -S 241 /dev/sdb

/dev/sdb:
 setting Advanced Power Management level to 0x7f (127)
 setting standby to 241 (30 minutes)
 APM_level  = 127

But the disk keeps spinning down after one minute. I tried other values for the -S option too, but the disk still keeps spinning down after one minute.

[root@localhost ~]# hdparm -I /dev/sdb

/dev/sdb:

ATA device, with non-removable media
    Model Number:       ST4000VN008-2DR166                      
    Serial Number:      ZDH1VA4J
    Firmware Revision:  SC60    
    Transport:          Serial, ATA8-AST, SATA 1.0a, SATA II Extensions, SATA Rev 2.5, SATA Rev 2.6, SATA Rev 3.0
Standards:
    Used: unknown (minor revision code 0x006d) 
    Supported: 10 9 8 7 6 5 
    Likely used: 10
Configuration:
    Logical     max current
    cylinders   16383   16383
    heads       16  16
    sectors/track   63  63
    --
    CHS current addressable sectors:    16514064
    LBA    user addressable sectors:   268435455
    LBA48  user addressable sectors:  7814037168
    Logical  Sector size:                   512 bytes
    Physical Sector size:                  4096 bytes
    Logical Sector-0 offset:                  0 bytes
    device size with M = 1024*1024:     3815447 MBytes
    device size with M = 1000*1000:     4000787 MBytes (4000 GB)
    cache/buffer size  = 8192 KBytes
    Form Factor: 3.5 inch
    Nominal Media Rotation Rate: 5980
Capabilities:
    LBA, IORDY(can be disabled)
    Queue depth: 32
    Standby timer values: spec'd by Standard, no device specific minimum
    R/W multiple sector transfer: Max = 16  Current = 16
    Advanced power management level: 127
    Recommended acoustic management value: 254, current value: 0
    DMA: mdma0 mdma1 mdma2 udma0 udma1 udma2 udma3 udma4 udma5 *udma6 
         Cycle time: min=120ns recommended=120ns
    PIO: pio0 pio1 pio2 pio3 pio4 
         Cycle time: no flow control=120ns  IORDY flow control=120ns
Commands/features:
    Enabled Supported:
       *    SMART feature set
            Security Mode feature set
       *    Power Management feature set
       *    Write cache
       *    Look-ahead
       *    Host Protected Area feature set
       *    WRITE_BUFFER command
       *    READ_BUFFER command
       *    DOWNLOAD_MICROCODE
       *    Advanced Power Management feature set
            Power-Up In Standby feature set
       *    SET_FEATURES required to spinup after power up
            SET_MAX security extension
       *    48-bit Address feature set
       *    Device Configuration Overlay feature set
       *    Mandatory FLUSH_CACHE
       *    FLUSH_CACHE_EXT
       *    SMART error logging
       *    SMART self-test
       *    Media Card Pass-Through
       *    General Purpose Logging feature set
       *    WRITE_{DMA|MULTIPLE}_FUA_EXT
       *    64-bit World wide name
       *    IDLE_IMMEDIATE with UNLOAD
            Write-Read-Verify feature set
       *    WRITE_UNCORRECTABLE_EXT command
       *    {READ,WRITE}_DMA_EXT_GPL commands
       *    Segmented DOWNLOAD_MICROCODE
       *    unknown 119[6]
       *    Gen1 signaling speed (1.5Gb/s)
       *    Gen2 signaling speed (3.0Gb/s)
       *    Gen3 signaling speed (6.0Gb/s)
       *    Native Command Queueing (NCQ)
       *    Phy event counters
       *    Idle-Unload when NCQ is active
       *    READ_LOG_DMA_EXT equivalent to READ_LOG_EXT
       *    DMA Setup Auto-Activate optimization
            Device-initiated interface power management
       *    Software settings preservation
            unknown 78[7]
            unknown 78[11]
       *    SMART Command Transport (SCT) feature set
       *    SCT Write Same (AC2)
       *    SCT Error Recovery Control (AC3)
       *    SCT Features Control (AC4)
       *    SCT Data Tables (AC5)
            unknown 206[7]
            unknown 206[12] (vendor specific)
            unknown 206[14] (vendor specific)
       *    SANITIZE_ANTIFREEZE_LOCK_EXT command
       *    SANITIZE feature set
       *    OVERWRITE_EXT command
       *    DOWNLOAD MICROCODE DMA command
Security: 
    Master password revision code = 65534
        supported
    not ...