怎麼解fdisk切出來的partition比實際的小 « Terrence的宅宅幻想
阿新 • • 發佈：2018-12-17
今天跟人要了一批機器，在初始化硬碟的時候遇到了用fdisk切出來的partition比用fdisk -l看的還小很多的情況
花了兩個小時研究終於找到解法，這邊紀錄一下
由於這次要的這批機器是別人用過的機種，在format硬碟的時候遇到了兩個狀況
狀況1: cannot write disk label: Invalid argument
partition的label無法寫入
$ fdisk -l /dev/sdb
Command (m for help): n
Partition number (1-128, default 1):
First sector (34-750157790, default 2048):
Last sector, +sectors or +size{K,M,G,T,P} (2048-750157790, default 750157790):
Created partition 1
Command (m for help): w
fdisk: cannot write disk label: Invalid argument
狀況2: 切出來的partition比實際小很多
使用fdisk -l看的時候有1.3TB左右
$ fdisk -l /dev/sdb WARNING: fdisk GPT support is currently new, and therefore in an experimental phase. Use at your own discretion. Disk /dev/sdb: 1438.7 GB, 1438679826432 bytes, 2809921536 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 label type: gpt Disk identifier: 8A5FB6FB-4D7D-4BDC-8BFE-BCE7994F319F
但實際切出來只有300多GB
$ fdisk /dev/sdb
WARNING: fdisk GPT support is currently new, and therefore in an experimental phase. Use at your own discretion.
Welcome to fdisk (util-linux 2.23.2).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.
Command (m for help): n
Partition number (1-128, default 1):
First sector (34-750157790, default 2048):
Last sector, +sectors or +size{K,M,G,T,P} (2048-750157790, default 750157790):
Created partition 1
Command (m for help): p
Disk /dev/sdb: 1438.7 GB, 1438679826432 bytes, 2809921536 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 label type: gpt
Disk identifier: 8A5FB6FB-4D7D-4BDC-8BFE-BCE7994F319F
# Start End Size Type Name
1 2048 750157790 357.7G Linux filesyste
初步猜測是MBR裡面有一些舊資訊妨礙了fdisk
然後上網查了查詢到有一個更好用的工具gdisk，可以顯示更多資訊然後幫我們重建
試了一下，去切另一顆1.8TB的硬碟
$ yum install -y gdisk
$ gdisk /dev/sdc
GPT fdisk (gdisk) version 0.8.6
Caution: invalid backup GPT header, but valid main header; regenerating
backup header from main header.
Partition table scan:
MBR: hybrid
BSD: not present
APM: not present
GPT: damaged
Found valid MBR and corrupt GPT. Which do you want to use? (Using the
GPT MAY permit recovery of GPT data.)
1 - MBR
2 - GPT
3 - Create blank GPT
Your answer: 1
Warning! Secondary partition table overlaps the last partition by
33 blocks!
You will need to delete this partition or resize it in another utility.
Command (? for help): o
This option deletes all partitions and creates a new protective MBR.
Proceed? (Y/N): y
Command (? for help): n
Partition number (1-128, default 1):
First sector (34-3904896990, default = 2048) or {+-}size{KMGTP}:
Last sector (2048-3904896990, default = 3904896990) or {+-}size{KMGTP}:
Current type is 'Linux filesystem'
Hex code or GUID (L to show codes, Enter = 8300):
Changed type of partition to 'Linux filesystem'
Command (? for help): p
Disk /dev/sdc: 3904897024 sectors, 1.8 TiB
Logical sector size: 512 bytes
Disk identifier (GUID): 053E1BA2-8455-4B03-A39D-CDA708C1F8C5
Partition table holds up to 128 entries
First usable sector is 34, last usable sector is 3904896990
Partitions will be aligned on 2048-sector boundaries
Total free space is 2014 sectors (1007.0 KiB)
Number Start (sector) End (sector) Size Code Name
1 2048 3904896990 1.8 TiB 8300 Linux filesystem
Command (? for help): w
Final checks complete. About to write GPT data. THIS WILL OVERWRITE EXISTING
PARTITIONS!!
Do you want to proceed? (Y/N): y
OK; writing new GUID partition table (GPT) to /dev/sdc.
The operation has completed successfully.
$ mkfs.ext4 /dev/sdc1
成功了!!，切出了原本disk的大小
主要多做了一個動作
Command (? for help): o This option deletes all partitions and creates a new protective MBR. Proceed? (Y/N): y
在切partition之前先建立一個新的MBR，就解決了上面的問題