如何不用重启在CentOS 7/ RHEL 7虚拟机中添加一块新硬盘
通常在你在虚拟机中添加一块新硬盘时，你可能会看到新硬盘没有自动加载。这是因为连接到硬盘的SCSI总线需要重新扫描来使得新硬盘可见。这里有一个简单的命令来重新扫描SCSI总线和SCSI设备。下面这几步在CentOS 7 和RHEL 7 中测试过。在ESXi或者vCenter中添加一块新的20G硬盘：显示当前磁盘分区：[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 确定主机总线号[root@centos7 ~]# ls /sys/class/scsi_host/ host0 host1 host2 重新扫描SCSI总线来添加设备[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 验证磁盘和分区并确保20GB硬盘已经添加了。在本例中，出现了下面这行 “Disk /dev/sdb: 21.5 GB, 21474836480 bytes, 41943040 sectors” 并且可以确认没有重启服务器就添加了新盘：[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 via: http://www.ehowstuff.com/how-to-add-a-new-hard-disk-without-rebooting-on-centos-7-rhel-7/作者：skytech 译者：geekpi 校对：wxy本文由 LCTT 原创翻译，Linux中国 荣誉推出