我今天刚买了一个8TB的硬盘。
我只是把它放在我的 USB 外壳中。
fdisk -l确实看到了设备：
Disk /dev/sdc: 1404.5 GB, 1404493455360 bytes, 2743151280 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
但是大小不对，fdisk认为只有 1.4TB。
df也无法正确识别尺寸：
$ df /dev/sdc
Filesystem 1K-blocks Used Available Use% Mounted on
devtmpfs 8078104 0 8078104 0% /dev
然后，我sudo fdisk /dev/sdc尝试删除所有分区（但没有）并创建一个新的分区：
Command (m for help): d
No partition is defined yet!
Command (m for help): n
Partition type:
p primary (0 primary, 0 extended, 4 free)
e extended
Select (default p): p
Partition number (1-4, default 1): 1
First sector (2048-2743151279, default 2048):
Using default value 2048
Last sector, +sectors or +size{K,M,G} (2048-2743151279, default 2743151279):
Using default value 2743151279
Partition 1 of type Linux and of size 1.3 TiB is set
知道为什么丢失了 6.5TB 吗？我该如何找回它们？
谢谢！
更新 #1：按照 James 的建议，smartctl确实显示有 8TB。所以只剩下第二个问题——如何恢复它们？
smartctl 6.2 2013-07-26 r3841 [x86_64-linux-3.10.0-862.2.3.el7.x86_64] (local build)
Copyright (C) 2002-13, Bruce Allen, Christian Franke, www.smartmontools.org
=== START OF INFORMATION SECTION ===
Device Model: HGST HDN728080ALE604
Serial Number: ........
LU WWN Device Id: ........
Firmware Version: A4GNW91X
User Capacity: 8,001,563,222,016 bytes [8.00 TB]
Sector Sizes: 512 bytes logical, 4096 bytes physical
Rotation Rate: 7200 rpm
Device is: Not in smartctl database [for details use: -P showall]
ATA Version is: ACS-2, ATA8-ACS T13/1699-D revision 4
SATA Version is: SATA 3.1, 6.0 Gb/s (current: 3.0 Gb/s)
Local Time is: Fri Feb 15 20:29:41 2019
SMART support is: Available - device has SMART capability.
SMART support is: Enabled
=== START OF READ SMART DATA SECTION ===
SMART overall-health self-assessment test result: PASSED
General SMART Values:
Offline data collection status: (0x80) Offline data collection activity
was never started.
Auto Offline Data Collection: Enabled.
Self-test execution status: ( 0) The previous self-test routine completed
without error or no self-test has ever
been run.
Total time to complete Offline
data collection: ( 101) seconds.
Offline data collection
capabilities: (0x5b) SMART execute Offline immediate.
Auto Offline data collection on/off support.
Suspend Offline collection upon new
command.
Offline surface scan supported.
Self-test supported.
No Conveyance Self-test supported.
Selective Self-test supported.
SMART capabilities: (0x0003) Saves SMART data before entering
power-saving mode.
Supports SMART auto save timer.
Error logging capability: (0x01) Error logging supported.
General Purpose Logging supported.
Short self-test routine
recommended polling time: ( 2) minutes.
Extended self-test routine
recommended polling time: (1184) minutes.
SCT capabilities: (0x003d) SCT Status supported.
SCT Error Recovery Control supported.
SCT Feature Control supported.
SCT Data Table supported.
SMART Attributes Data Structure revision number: 16
Vendor Specific SMART Attributes with Thresholds:
ID# ATTRIBUTE_NAME FLAG VALUE WORST THRESH TYPE UPDATED WHEN_FAILED RAW_VALUE
1 Raw_Read_Error_Rate 0x000b 100 100 016 Pre-fail Always - 0
2 Throughput_Performance 0x0005 100 100 054 Pre-fail Offline - 0
3 Spin_Up_Time 0x0007 100 100 024 Pre-fail Always - 0
4 Start_Stop_Count 0x0012 100 100 000 Old_age Always - 4
5 Reallocated_Sector_Ct 0x0033 100 100 005 Pre-fail Always - 0
7 Seek_Error_Rate 0x000b 100 100 067 Pre-fail Always - 0
8 Seek_Time_Performance 0x0005 100 100 020 Pre-fail Offline - 0
9 Power_On_Hours 0x0012 100 100 000 Old_age Always - 0
10 Spin_Retry_Count 0x0013 100 100 060 Pre-fail Always - 0
12 Power_Cycle_Count 0x0032 100 100 000 Old_age Always - 4
22 Unknown_Attribute 0x0023 100 100 025 Pre-fail Always - 100
192 Power-Off_Retract_Count 0x0032 100 100 000 Old_age Always - 6
193 Load_Cycle_Count 0x0012 100 100 000 Old_age Always - 6
194 Temperature_Celsius 0x0002 222 222 000 Old_age Always - 27 (Min/Max 23/33)
196 Reallocated_Event_Count 0x0032 100 100 000 Old_age Always - 0
197 Current_Pending_Sector 0x0022 100 100 000 Old_age Always - 0
198 Offline_Uncorrectable 0x0008 100 100 000 Old_age Offline - 0
199 UDMA_CRC_Error_Count 0x000a 200 200 000 Old_age Always - 0
SMART Error Log Version: 1
No Errors Logged
SMART Self-test log structure revision number 1
No self-tests have been logged. [To run self-tests, use: smartctl -t]
SMART Selective self-test log data structure revision number 1
SPAN MIN_LBA MAX_LBA CURRENT_TEST_STATUS
1 0 0 Not_testing
2 0 0 Not_testing
3 0 0 Not_testing
4 0 0 Not_testing
5 0 0 Not_testing
Selective self-test flags (0x0):
After scanning selected spans, do NOT read-scan remainder of disk.
If Selective self-test is pending on power-up, resume after 0 minute delay.
更新＃2：现在，我直接连接到 HDD，而不是通过 USB + 外壳。
fdisk显示正确的总大小为 8TB：
Disk /dev/sdc: 8001.6 GB, 8001563222016 bytes, 15628053168 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
然而，df仍然只显示1.22TB：
$ df
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/sdc 1349915988 77848 1281242976 1% /run/media/myuser/xyz
以下是具体内容/proc/partitions：
$ sudo grep sdc /proc/partitions
8 32 7814026584 sdc
任何想法？
答案1
您的 USB 外壳仅支持 32 位 LBA。这对于大于 2 TiB 的驱动器来说不够用。
根据smartctl，您的驱动器为 8,001,563,222,016 字节，这意味着 15,628,053,168 个 512 字节扇区。但是，您的 USB 外壳报告有 2,743,151,280 个扇区。如果我们看一下二进制表示，问题就很明显了：
15,628,053,168 = 11 1010 0011 1000 0001 0010 1010 1011 0000
2,743,151,280 = 1010 0011 1000 0001 0010 1010 1011 0000
买一个新的、现代的 USB 外壳。固件更新可能会有所帮助，但可能没有可用的。
答案2
您需要运行smartctl来显示设备信息：
smartctl -a /dev/sdc
（如果未安装 smartctl，则需要执行yum install smartmontools）
这应该向您显示包含顶部“信息部分”的输出，其中应包含（除其他外）制造商，型号和序列号 - 例如：
=== START OF INFORMATION SECTION ===
Model Family: Western Digital Red
Device Model: WDC WD60EFRX-68L0BN1
Serial Number: ...elided...
LU WWN Device Id: ...elided...
Firmware Version: 82.00A82
User Capacity: 6,001,175,126,016 bytes [6.00 TB]
如果这没有显示你期望的内容，那么它要么不是一个 8TB 的硬盘，或者你可能看错了硬盘？