公司有台服務器做了raid1，由於容量小，需擴容，原先打算再添加兩塊硬盤進去做多一組raid1，組成兩組raid1混合使用，但是公司摳門，買到服務器只能安裝3塊硬盤，無奈之下只能放多一塊進去單獨掛載分區使用。
開始的時候把新加的硬盤接入raid卡，服務器開機無法識別，解決方法是把新加的硬盤接入主板的SATA接口，服務器開機登錄后順利識別到。
先說說開始時候的操作方法：
首先用fdisk進行分區
# fdisk /dev/sdb
整塊硬盤全部空間只建立一個分區，分完區后查看
Disk /dev/sdb: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x0005f698
Device Boot Start End Blocks Id System
/dev/sdb1 1 121601 976760001 83 Linux
可以看到建立了一個新分區/dev/sdb1
然后進行格式化並掛載分區
# mkfs -t ext4 -c /dev/sdb1 (快速格式化：mkfs.ext4 /dev/sdb1)
mke2fs 1.41.12 (17-May-2010)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
61054976 inodes, 244190000 blocks
12209500 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=4294967296
7453 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,
4096000, 7962624, 11239424, 20480000, 23887872, 71663616, 78675968,
102400000, 214990848
Checking for bad blocks (read-only test): done
Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done
This filesystem will be automatically checked every 24 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
# mount /dev/sdb1 /data
# df -h
可以看到已經成功掛載了
修改/etc/fstab，添加下面這行，使之開機自動掛載
/dev/sdb1 /data ext4 defaults 0 0
保存后重啟服務器init 6
執行df -h發現竟然沒有掛載成功
執行fdisk -l還能看到/dev/sdb1分區
Disk /dev/sdb: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x0005f698
Device Boot Start End Blocks Id System
/dev/sdb1 1 121601 976760001 83 Linux
但是沒有存在/dev/sdb1
# ll /dev/sdb1
ls: cannot access /dev/sdb1: No such file or directory
重新執行掛載
# mount /dev/sdb1 /data/
mount: you must specify the filesystem type
加上分區類型重新掛載，提示不存在分區
# mount -t ext4 /dev/sdb1 /data/
mount: special device /dev/sdb1 does not exist
按照網上大神的方法，成功解決：
# mkfs.ext4 /dev/sdb
mke2fs 1.41.12 (17-May-2010)
/dev/sdb is entire device, not just one partition!
Proceed anyway? (y,n) y
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
61054976 inodes, 244190646 blocks
12209532 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=4294967296
7453 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,
4096000, 7962624, 11239424, 20480000, 23887872, 71663616, 78675968,
102400000, 214990848
Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done
This filesystem will be automatically checked every 23 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
格式化整塊硬盤
格式化完畢后fdisk -l查看
Disk /dev/sdb: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000
沒有了/dev/sdb1分區
重新掛載
# mount /dev/sdb /data/
# df -h
成功掛載，修改/etc/fstab使之開機自動掛載，添加以下內容
/dev/sdb /data ext4 defaults 0 0
init 6重啟后發現能正常自動掛載，到此已成功解決問題
用lsblk命令查看已識別的硬盤和掛載的分區
# lsblk
