CentOS在不重啟的情況下為其虛擬機器添加新硬碟的教程

 　　通常在你在虛擬機器中添加一塊新硬碟時，你可能會看到新硬碟沒有自動載入。這是因為串連到硬碟的SCSI匯流排需要重新掃描來使得新硬碟可見。這裡有一個簡單的命令來重新掃描SCSI匯流排和SCSI裝置。下面這幾步在CentOS 7 和RHEL 7 中測試過。

　　在ESXi或者vCenter中添加一塊新的20G硬碟：

　　顯示當前磁碟分割：

　　代碼如下:

　　[root@centos7 ~]# fdisk -l

Disk /dev/sda: 32.2 GB, 32212254720 bytes, 62914560 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: dos

　　Disk identifier: 0x0006b96a

　　Device Boot Start End Blocks Id System

　　/dev/sda1 * 2048 1026047 512000 83 Linux

　　/dev/sda2 1026048 62914559 30944256 8e Linux LVM

　　Disk /dev/mapper/centos-swap: 2147 MB, 2147483648 bytes, 4194304 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 /dev/mapper/centos-root: 29.5 GB, 29536288768 bytes, 57688064 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

　　確定主機匯流排號

　　代碼如下:

　　[root@centos7 ~]# ls /sys/class/scsi_host/

　　host0 host1 host2

　　重新掃描SCSI匯流排來添加裝置

　　代碼如下:

　　[root@centos7 ~]# echo "- - -" > /sys/class/scsi_host/host0/scan

　　[root@centos7 ~]# echo "- - -" > /sys/class/scsi_host/host1/scan

　　[root@centos7 ~]# echo "- - -" > /sys/class/scsi_host/host2/scan

　　驗證磁碟和分區並確保20GB硬碟已經添加了。在本例中，出現了下面這行 “Disk /dev/sdb: 21.5 GB, 21474836480 bytes, 41943040 sectors” 並且可以確認沒有重啟伺服器就添加了新盤：

　　代碼如下:

　　[root@centos7 ~]# fdisk -l

　　Disk /dev/sda: 32.2 GB, 32212254720 bytes, 62914560 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: dos

　　Disk identifier: 0x0006b96a

　　Device Boot Start End Blocks Id System

　　/dev/sda1 * 2048 1026047 512000 83 Linux

　　/dev/sda2 1026048 62914559 30944256 8e Linux LVM

　　Disk /dev/mapper/centos-swap: 2147 MB, 2147483648 bytes, 4194304 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 /dev/mapper/centos-root: 29.5 GB, 29536288768 bytes, 57688064 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 /dev/sdb: 21.5 GB, 21474836480 bytes, 41943040 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