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。

1. 在ESXi或者vCenter中添加一块新的20G硬盘：

   

2. 显示当前磁盘分区：

   1. [root@centos7 ~]# fdisk -l

   ---

   1. Disk/dev/sda:32.2 GB,32212254720 bytes,62914560 sectors
   2. Units= sectors of 1*512=512 bytes
   3. Sector size (logical/physical):512 bytes /512 bytes
   4. I/O size (minimum/optimal):512 bytes /512 bytes
   5. Disk label type: dos
   6. Disk identifier:0x0006b96a
   7. DeviceBootStartEndBlocksIdSystem
   8. /dev/sda1 *2048102604751200083Linux
   9. /dev/sda2 102604862914559309442568eLinux LVM
   10. Disk/dev/mapper/centos-swap:2147 MB,2147483648 bytes,4194304 sectors
   11. Units= sectors of 1*512=512 bytes
   12. Sector size (logical/physical):512 bytes /512 bytes
   13. I/O size (minimum/optimal):512 bytes /512 bytes
   14. Disk/dev/mapper/centos-root:29.5 GB,29536288768 bytes,57688064 sectors
   15. Units= sectors of 1*512=512 bytes
   16. Sector size (logical/physical):512 bytes /512 bytes
   17. I/O size (minimum/optimal):512 bytes /512 bytes

3. 确定主机总线号

   1. [root@centos7 ~]# ls /sys/class/scsi_host/
   2. host0 host1 host2

4. 重新扫描SCSI总线来添加设备

   1. [root@centos7 ~]# echo "- - -">/sys/class/scsi_host/host0/scan
   2. [root@centos7 ~]# echo "- - -">/sys/class/scsi_host/host1/scan
   3. [root@centos7 ~]# echo "- - -">/sys/class/scsi_host/host2/scan

5. 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：

   1. [root@centos7 ~]# fdisk -l
   2. Disk/dev/sda:32.2 GB,32212254720 bytes,62914560 sectors
   3. Units= sectors of 1*512=512 bytes
   4. Sector size (logical/physical):512 bytes /512 bytes
   5. I/O size (minimum/optimal):512 bytes /512 bytes
   6. Disk label type: dos
   7. Disk identifier:0x0006b96a
   8. DeviceBootStartEndBlocksIdSystem
   9. /dev/sda1 *2048102604751200083Linux
   10. /dev/sda2 102604862914559309442568eLinux LVM
   11. Disk/dev/mapper/centos-swap:2147 MB,2147483648 bytes,4194304 sectors
   12. Units= sectors of 1*512=512 bytes
   13. Sector size (logical/physical):512 bytes /512 bytes
   14. I/O size (minimum/optimal):512 bytes /512 bytes
   15. Disk/dev/mapper/centos-root:29.5 GB,29536288768 bytes,57688064 sectors
   16. Units= sectors of 1*512=512 bytes
   17. Sector size (logical/physical):512 bytes /512 bytes
   18. I/O size (minimum/optimal):512 bytes /512 bytes
   19. Disk/dev/sdb:21.5 GB,21474836480 bytes,41943040 sectors
   20. Units= sectors of 1*512=512 bytes
   21. Sector size (logical/physical):512 bytes /512 bytes
   22. I/O size (minimum/optimal):512 bytes /512 bytes

更多CentOS相关信息见CentOS 专题页面 http://www.linuxidc.com/topicnews.aspx?tid=14

本文永久更新链接地址：http://www.linuxidc.com/Linux/2015-03/115619.htm