X86的debian10加了一块4T硬盘已加载EXT4分区，最近发现写入速度忽高忽低。机器一共两块硬盘在sata接口上，其中一块1TB，写入读取速度正常，就是新加入的这个4T不行。一下写入120M，一下又跌到0，然后再起来，如此反复。。。。对比两块硬盘信息，貌似不同的地方只有cache/buffer size 不同，新加入的4T显示unknown，不知道是否与这个有点关系，请各位大神指点!
附上hdparm -I信息：
4TB：
ATA device, with non-removable media
Model Number: WDC WD4002FYYZ-01B7CB0
Serial Number: MMBBB123
Firmware Revision: 01.01M02
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: 9 8 7 6 5
Likely used: 9
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: 512 bytes
device size with M = 10241024: 3815447 MBytes
device size with M = 10001000: 4000787 MBytes (4000 GB)
cache/buffer size = unknown
Form Factor: 3.5 inch
Nominal Media Rotation Rate: 7200
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: 254
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
====================================================================
1TB：
ATA device, with non-removable media
Model Number: WDC WD10JPVX-00ccvv
Serial Number: WD-63WXD1EB3XXS
Firmware Revision: 01.01A01
Transport: Serial, SATA 1.0a, SATA II Extensions, SATA Rev 2.5, SATA Rev 2.6, SATA Rev 3.0
Standards:
Supported: 9 8 7 6 5
Likely used: 9
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: 1953525168
Logical Sector size: 512 bytes
Physical Sector size: 4096 bytes
Logical Sector-0 offset: 0 bytes
device size with M = 10241024: 953869 MBytes
device size with M = 10001000: 1000204 MBytes (1000 GB)
cache/buffer size = 8192 KBytes
Nominal Media Rotation Rate: 5400
Capabilities:
LBA, IORDY(can be disabled)
Queue depth: 32
Standby timer values: spec’d by Standard, with device specific minimum
R/W multiple sector transfer: Max = 16 Current = 16
Advanced power management level: 254
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
1TB读写速度都正常！！！