「デバイス /dev/mappper/mpath25 が見つかりません (またはフィルタリングによって無視されます)」 – pvcreate で物理ボリュームを作成中にエラーが発生しました

問題

物理ボリュームを作成しようとすると、以下のエラーが発生します

エラー:

# pvcreate /dev/mappper/mpath25
Device /dev/mappper/mpath25 not found (or ignored by filtering).

この問題は、次の手順で自由に再現できます:

# pvcreate /dev/mappper/mpath25

解決策

チェックすると、開始セクタがゼロに設定されていないことがわかりました。

# pvcreate /dev/mappper/mpath25
Device /dev/mappper/mpath25 not found (or ignored by filtering).

# fdisk -l /dev/mapper/mpath25
Disk /dev/mapper/mpath25 doesn't contain a valid partition table

これは、ディスク上に何も存在しなかったことを示しています。詳細オプション「-vvv」を指定して pvcreate コマンドを実行すると、エラーの詳細を取得できます:

# pvcreate -vvv /dev/mapper/mpath25
Processing: pvcreate -vvv /dev/mapper/mpath25
O_DIRECT will be used
Setting global/locking_type to 1
Setting global/wait_for_locks to 1
File-based locking selected.
Setting global/locking_dir to /var/lock/lvm
metadata/pvmetadataignore not found in config: defaulting to n
metadata/pvmetadatasize not found in config: defaulting to 255
metadata/pvmetadatacopies not found in config: defaulting to 1
Locking /var/lock/lvm/P_orphans WB
_do_flock /var/lock/lvm/P_orphans:aux WB
_do_flock /var/lock/lvm/P_orphans WB
_undo_flock /var/lock/lvm/P_orphans:aux
dm version OF [16384]
dm status (253:11) OF [16384]
/dev/mapper/mpath25: New preferred name      ### indicates that it can find the device
Opened /dev/mapper/mpath25 RO O_DIRECT
/dev/mapper/mpath25: size is 629145600 sectors
Closed /dev/mapper/mpath25
/dev/mapper/mpath25: size is 629145600 sectors
Opened /dev/mapper/mpath25 RO O_DIRECT
/dev/mapper/mpath25: block size is 4096 bytes
Closed /dev/mapper/mpath25
Using /dev/mapper/mpath25
Opened /dev/mapper/mpath25 RO O_DIRECT
/dev/mapper/mpath25: block size is 4096 bytes
/dev/mapper/mpath25: No label detected
Closed /dev/mapper/mpath25
dm status (253:11) OF [16384]
Opened /dev/mapper/mpath25 RO O_DIRECT
/dev/mapper/mpath25: size is 629145600 sectors
Closed /dev/mapper/mpath25
/dev/mapper/mpath25: size is 629145600 sectors
Opened /dev/mapper/mpath25 RO O_DIRECT
/dev/mapper/mpath25: block size is 4096 bytes
Closed /dev/mapper/mpath25
Using /dev/mapper/mpath25
Opened /dev/mapper/mpath25 RW O_EXCL O_DIRECT
Closed /dev/mapper/mpath25
/dev/mapper/mpath25: size is 629145600 sectors
Opened /dev/mapper/mpath25 RO O_DIRECT
/dev/mapper/mpath25: block size is 4096 bytes
Closed /dev/mapper/mpath25
/dev/mapper/mpath25: size is 629145600 sectors
Opened /dev/mapper/mpath25 RO O_DIRECT
/dev/mapper/mpath25: block size is 4096 bytes
Closed /dev/mapper/mpath25
Opened /dev/mapper/mpath25 RO O_DIRECT
/dev/mapper/mpath25: block size is 4096 bytes
Closed /dev/mapper/mpath25
dm status (253:11) OF [16384]
Opened /dev/mapper/mpath25 RO O_DIRECT
/dev/mapper/mpath25: size is 629145600 sectors
Closed /dev/mapper/mpath25
/dev/mapper/mpath25: size is 629145600 sectors
Opened /dev/mapper/mpath25 RO O_DIRECT
/dev/mapper/mpath25: block size is 4096 bytes
Closed /dev/mapper/mpath25
Using /dev/mapper/mpath25
/dev/mapper/mpath25: size is 629145600 sectors
Setting devices/data_alignment to 0
Setting devices/default_data_alignment to 0
/dev/mapper/mpath25: Setting PE alignment to 128 sectors.
/dev/mapper/mpath25: Setting PE alignment offset to 0 sectors.
Opened /dev/mapper/mpath25 RW O_DIRECT
Wiping /dev/mapper/mpath25 at sector 8 length 8 sectors
/dev/mapper/mpath25: block size is 4096 bytes
Closed /dev/mapper/mpath25
Set up physical volume for "/dev/mapper/mpath25" with 629145600 available sectors
Scanning for labels to wipe from /dev/mapper/mpath25
Opened /dev/mapper/mpath25 RW O_DIRECT
/dev/mapper/mpath25: block size is 4096 bytes
Closed /dev/mapper/mpath25
Zeroing start of device /dev/mapper/mpath25
Opened /dev/mapper/mpath25 RW O_DIRECT
Wiping /dev/mapper/mpath25 at sector 0 length 4 sectors
/dev/mapper/mpath25: block

原因が最初のセクタ領域のゼロ化にあることを示すデバッグ出力の最後のエントリ。

ソリューションを実装するには、次の手順を実行してください:

1. ディスク デバイス全体の場合、パーティション テーブルのみを消去する必要があります。これにより、そのディスク上のすべてのデータが効果的に破壊されます。これは、次の方法で最初のセクターをゼロにすることで実行できます:

# dd if=/dev/zero of= bs=512 count=1.

2. pvcreate を実行して物理ボリュームを作成します:

# pvcreate [device]

3. 必要に応じてソリューションを他の環境に移行します。