本文主要是一些和硬盘相关的命令，包括如何查看硬盘的型号，容量，还有硬盘上的分区情况，来详细了解本机硬盘的状态。

hdparm

如果想要在 Linux 下查看硬盘信息，可以使用命令 hdparm 。这个命令可以用来查看硬盘制造商，序列号等等有用信息。man hdparm 中告诉我， hdparm 命令是用来查看或者设置 SATA/IDE 设备参数的。

查看设备信息

假设本地有设备 /dev/sda 那么可以使用

hdparm -I /dev/sda

来查看该设备的信息

/dev/sda:

ATA device, with non-removable media

Model Number: Netac SSD 240G

Serial Number: 5002B725438XXXX

Firmware Revision: O1217A

Transport: Serial, ATA8-AST, 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: 468862128

Logical Sector size: 512 bytes

Physical Sector size: 512 bytes

Logical Sector-0 offset: 0 bytes

device size with M = 1024*1024: 228936 MBytes

device size with M = 1000*1000: 240057 MBytes (240 GB)

cache/buffer size = unknown

Nominal Media Rotation Rate: Solid State Device

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 = 2 Current = 2

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

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

* General Purpose Logging feature set

* WRITE_{DMA|MULTIPLE}_FUA_EXT

* {READ,WRITE}_DMA_EXT_GPL commands

* Segmented DOWNLOAD_MICROCODE

* 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

* READ_LOG_DMA_EXT equivalent to READ_LOG_EXT

* DMA Setup Auto-Activate optimization

Device-initiated interface power management

* Software settings preservation

Device Sleep (DEVSLP)

* SMART Command Transport (SCT) feature set

* SCT Write Same (AC2)

* SCT Features Control (AC4)

* SCT Data Tables (AC5)

* DOWNLOAD MICROCODE DMA command

* WRITE BUFFER DMA command

* READ BUFFER DMA command

* Data Set Management TRIM supported (limit 8 blocks)

* Deterministic read ZEROs after TRIM

Security:

Master password revision code = 65534

supported

not enabled

not locked

frozen

not expired: security count

supported: enhanced erase

2min for SECURITY ERASE UNIT. 2min for ENHANCED SECURITY ERASE UNIT.

Device Sleep:

DEVSLP Exit Timeout (DETO): 40 ms (drive)

Minimum DEVSLP Assertion Time (MDAT): 31 ms (drive)

Checksum: correct

测试读取速度

hdparm 提供了一个简单的读速度测试参数

hdparm -Tt /dev/sda

结果

/dev/sda:

Timing cached reads: 25572 MB in 2.00 seconds = 12798.56 MB/sec

Timing buffered disk reads: 800 MB in 3.01 seconds = 266.08 MB/sec

能够看到 2 秒内读取了 25572M 缓存，而在 3 秒内从磁盘上物理读 800M 数据。

fdisk

fdisk 主要用来查看和修改硬盘分区表，它能够识别 GPT，MBR，BSD 等等分区表。设备可以被划分为一个或者若干逻辑磁盘，这些逻辑磁盘叫做分区。这些分区信息被包含在分区表 (partition table) 中，通常在硬盘的 sector 0 中保存。

设备名通常叫做 /dev/sda， /dev/sdb 等等，设备的名字通常指整块硬盘，分区名字通常是设备名后面加上分区的序号，比如 /dev/sda1 表示的是第一块硬盘上的一个分区。详细的信息可以在 Linux kernel 文档 Documentation/devices.txt 文件中找到。

GPT

GPT 的全称是 GUID Partition Table，全局唯一标识分区表，指的是一个实体硬盘的分区表结构布局标准。

MBR

MBR 全称为 Master Boot Record，主引导扇区， DOS type。Sector 0 是被 4 个主分区 primary partition 描述占用的，逻辑分区 (Logical partition) 从序号 5 开始。

如果要查看硬盘的分区情况，可以使用 fdisk

fdisk -l

结果

Disk /dev/loop0: 81.7 MiB, 85692416 bytes, 167368 sectors

Units: sectors of 1 * 512 = 512 bytes

Sector size (logical/physical): 512 bytes / 512 bytes

I/O size (minimum/optimal): 512 bytes / 512 bytes

Disk /dev/loop1: 81.7 MiB, 85639168 bytes, 167264 sectors

Units: sectors of 1 * 512 = 512 bytes

Sector size (logical/physical): 512 bytes / 512 bytes

I/O size (minimum/optimal): 512 bytes / 512 bytes

Disk /dev/loop2: 81.6 MiB, 85549056 bytes, 167088 sectors

Units: sectors of 1 * 512 = 512 bytes

Sector size (logical/physical): 512 bytes / 512 bytes

I/O size (minimum/optimal): 512 bytes / 512 bytes

Disk /dev/sda: 223.6 GiB, 240057409536 bytes, 468862128 sectors

Units: sectors of 1 * 512 = 512 bytes

Sector size (logical/physical): 512 bytes / 512 bytes

I/O size (minimum/optimal): 512 bytes / 512 bytes

Disklabel type: dos

Disk identifier: 0x5ad18deb

Device Boot Start End Sectors Size Id Type

/dev/sda1 63 468862127 468862065 223.6G 83 Linux

Disk /dev/sdb: 931.5 GiB, 1000204886016 bytes, 1953525168 sectors

Units: sectors of 1 * 512 = 512 bytes

Sector size (logical/physical): 512 bytes / 4096 bytes

I/O size (minimum/optimal): 4096 bytes / 4096 bytes

Disklabel type: dos

Disk identifier: 0x29049925

Device Boot Start End Sectors Size Id Type

/dev/sdb1 * 63 629153594 629153532 300G 7 HPFS/NTFS/exFAT

/dev/sdb2 629153656 1953523711 1324370056 631.5G f W95 Ext'd (LBA)

/dev/sdb5 629153658 1153466999 524313342 250G 7 HPFS/NTFS/exFAT

/dev/sdb6 1153467063 1782588464 629121402 300G 7 HPFS/NTFS/exFAT

/dev/sdb7 1782589440 1798213631 15624192 7.5G 82 Linux swap / Solaris

/dev/sdb8 1798215680 1953523711 155308032 74.1G 83 Linux

Partition 1 does not start on physical sector boundary.

Partition 5 does not start on physical sector boundary.

Partition 6 does not start on physical sector boundary.

Disk /dev/sdc: 119.2 GiB, 128035676160 bytes, 250069680 sectors

Units: sectors of 1 * 512 = 512 bytes

Sector size (logical/physical): 512 bytes / 512 bytes

I/O size (minimum/optimal): 512 bytes / 512 bytes

Disklabel type: dos

Disk identifier: 0x326f11b9

Device Boot Start End Sectors Size Id Type

/dev/sdc1 * 63 248346992 248346930 118.4G 7 HPFS/NTFS/exFAT

/dev/sdc2 248348672 250066943 1718272 839M 27 Hidden NTFS WinRE

dd

dd 工具是一个专业的测试工具，对测试结果不苛求可以用来做 IO 读写的简单评估。首先要了解两个特殊设备：

/dev/null 伪设备，回收站。写该文件不会产生 IO

/dev/zero 伪设备，会产生空字符流，对它不会产生 IO

dd 命令使用：

dd if=/dev/zero of=/tmp/test bs=1G count=1 oflag=dsync

if 用来设置 dd 命令读取的输入文件名

of dd 输出文件名

bs 设置 dd 命令读取的块大小

count dd 命令读取的块个数

oflag=dsync 使用同步 I/O 去除 caching 影响

综上

测试硬盘写速度

sync; dd if=/dev/zero of=tempfile bs=1M count=1024; sync

测试磁盘读速度

dd if=tempfile of=/dev/null bs=1M count=1024

GUI

同样在 Linux 下也可以使用 GUI 图形化的工具来查看，搜索菜单 Disks，然后就能查看当前电脑安装的硬盘了。

查看分区

使用命令 lsblk 查看。

https://en.wikipedia.org/wiki/GUID_Partition_Table ↩