Linux での HDD のフォーマット

たぶん厳密にはLinuxではディスクのフォーマットとは言わないのだと思うが、「パーティションつくってファイルシステムをつくる」は長いので。

新しいデバイスの特定

新しいディスクを接続したら、まずはどのデバイスかを特定する。

たいていは /dev/sdX (Xはa,b,...など)になっているから

ls /dev/sd*

とすれば、数字がないデバイスがあるはず。数字がないのはパーティションが存在しないから。これが新しいディスクの判別になる。

ちなみに物理的なディスクと /dev/sda, /dev/sdbとかいう紐づけはいつも同じとは限らない。たとえばマザーボードのポートを入れ替えれば変わる。

 ls /dev/sd*

/dev/sda   /dev/sdb   /dev/sdc  /dev/sdd1  /dev/sde1  /dev/sdf1  /dev/sdf5  /dev/sdg1
/dev/sda1  /dev/sdb1  /dev/sdd  /dev/sde   /dev/sdf   /dev/sdf2  /dev/sdg

パーティションを作成する

$ sudo gdisk /dev/sdc

GPT fdisk (gdisk) version 1.0.9

Partition table scan:
  MBR: not present
  BSD: not present
  APM: not present
  GPT: not present

Creating new GPT entries in memory.

Command (? for help): p

Disk /dev/sdc: 7814037168 sectors, 3.6 TiB
Model: WDC WD40EZAX-00C
Sector size (logical/physical): 512/4096 bytes
Disk identifier (GUID): 56D311FC-40F6-4595-A1EF-F22475078708
Partition table holds up to 128 entries
Main partition table begins at sector 2 and ends at sector 33
First usable sector is 34, last usable sector is 7814037134
Partitions will be aligned on 2048-sector boundaries
Total free space is 7814037101 sectors (3.6 TiB)

Number  Start (sector)    End (sector)  Size       Code  Name

Command (? for help): o

This option deletes all partitions and creates a new protective MBR.

Proceed? (Y/N): y

Command (? for help): p

Disk /dev/sdc: 7814037168 sectors, 3.6 TiB
Model: WDC WD40EZAX-00C
Sector size (logical/physical): 512/4096 bytes
Disk identifier (GUID): 1B330559-0C65-4A25-A4BD-1D27D0A8199F
Partition table holds up to 128 entries
Main partition table begins at sector 2 and ends at sector 33
First usable sector is 34, last usable sector is 7814037134
Partitions will be aligned on 2048-sector boundaries
Total free space is 7814037101 sectors (3.6 TiB)

Number  Start (sector)    End (sector)  Size       Code  Name

Command (? for help): n

Partition number (1-128, default 1): 1
First sector (34-7814037134, default = 2048) or {+-}size{KMGTP}:
Last sector (2048-7814037134, default = 7814035455) or {+-}size{KMGTP}:
Current type is 8300 (Linux filesystem)

Command (? for help): p

Disk /dev/sdc: 7814037168 sectors, 3.6 TiB
Model: WDC WD40EZAX-00C
Sector size (logical/physical): 512/4096 bytes
Disk identifier (GUID): 1B330559-0C65-4A25-A4BD-1D27D0A8199F
Partition table holds up to 128 entries
Main partition table begins at sector 2 and ends at sector 33
First usable sector is 34, last usable sector is 7814037134
Partitions will be aligned on 2048-sector boundaries
Total free space is 3693 sectors (1.8 MiB)

Number  Start (sector)    End (sector)  Size       Code  Name
   1            2048      7814035455   3.6 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.

確認するとこんな感じ:

$ ls /dev/sdc*

/dev/sdc  /dev/sdc1

ファイルシステムを作成する

$ sudo mkfs.ext4 /dev/sdc1

mke2fs 1.47.0 (5-Feb-2023)
Creating filesystem with 976754176 4k blocks and 244195328 inodes
Filesystem UUID: 50431c6a-4b22-47c9-a1f6-f1396a6cbee9
Superblock backups stored on blocks:
        32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,
        4096000, 7962624, 11239424, 20480000, 23887872, 71663616, 78675968,
        102400000, 214990848, 512000000, 550731776, 644972544

Allocating group tables: done
Writing inode tables: done
Creating journal (262144 blocks): done
Writing superblocks and filesystem accounting information: done