当读hdparm手册页，它说，-S值
驱动器使用它来确定关闭主轴电机以节省功率之前要等待多长时间（无磁盘活动）
使用hdparm -B 1 -K 1 -S 120 /dev/sd[d-z]输出配置驱动器时：
setting drive keep features to 1 (on) setting Advanced Power Management level to 0x01 (1) setting standby to 120 (10 minutes) APM_level = 1
初始驱动器状态hdparm -C /dev/sd[d-z]为“ 活动/空闲 ”。
所有这些/dev/sd[d-z]驱动器均具有相同的品牌和型号，未分区，未格式化和未安装。
之后等待15分钟，驱动状态仍然是“ 有功/无 ”。
仅当使用hdparm -y /dev/sd[d-z]该驱动器发出“强制IDE驱动器立即进入低功耗待机模式”时，才进入“ 待机 ”状态。
在hdparm指定的超时值之后，为什么驱动器没有进入低功耗待机状态？
其他一些驱动器规格源自 hdparm -I /dev/sdd
/dev/sdd:
ATA device, with non-removable media
Model Number: Hitachi HDS5C3020BLE630
Firmware Revision: MZ4OAAB0
Transport: Serial, ATA8-AST, SATA 1.0a, SATA II Extensions, SATA Rev 2.5, SATA Rev 2.6, SATA Rev 3.0; Revision: ATA8-AST T13 Project D1697 Revision 0b
Standards:
Used: unknown (minor revision code 0x0029)
Supported: 8 7 6 5
Likely used: 8
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: 3907029168
Logical Sector size: 512 bytes
Physical Sector size: 4096 bytes
Logical Sector-0 offset: 0 bytes
device size with M = 1024*1024: 1907729 MBytes
device size with M = 1000*1000: 2000398 MBytes (2000 GB)
cache/buffer size = 22756 KBytes (type=DualPortCache)
Form Factor: 3.5 inch
Nominal Media Rotation Rate: 5700
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: 1
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
* NOP cmd
* 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
* URG for READ_STREAM[_DMA]_EXT
* URG for WRITE_STREAM[_DMA]_EXT
* WRITE_UNCORRECTABLE_EXT command
* {READ,WRITE}_DMA_EXT_GPL commands
* Segmented DOWNLOAD_MICROCODE
unknown 119[7]
* Gen1 signaling speed (1.5Gb/s)
* Gen2 signaling speed (3.0Gb/s)
* Gen3 signaling speed (6.0Gb/s)
* Native Command Queueing (NCQ)
* Host-initiated interface power management
* Phy event counters
* NCQ priority information
Non-Zero buffer offsets in DMA Setup FIS
DMA Setup Auto-Activate optimization
Device-initiated interface power management
In-order data delivery
* Software settings preservation
* SMART Command Transport (SCT) feature set
* SCT Write Same (AC2)
* SCT Error Recovery Control (AC3)
* SCT Features Control (AC4)
* SCT Data Tables (AC5)
Security:
Master password revision code = 65534
supported
not enabled
not locked
frozen
not expired: security count
not supported: enhanced erase
416min for SECURITY ERASE UNIT.
Logical Unit WWN Device Identifier: 5000cca37dc106a3
NAA : 5
IEEE OUI : 000cca
Unique ID : 37dc106a3
Checksum: correct