假定在虚拟机当中添加了磁盘，但是虚拟机没有识别出来；如何识别出来
可以使用命令
echo '- - -' >/sys/class/scsi_host/host0/scan
使用后就可以识别出来了
###增加两块硬盘 默认是不会识别
[root@compute1 ~]# fdisk -l
Disk /dev/sda: 53.7 GB, 53687091200 bytes, 104857600 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: 0x0009fb23
Device Boot Start End Blocks Id System
/dev/sda1 2048 4196351 2097152 82 Linux swap / Solaris
/dev/sda2 * 4196352 104857599 50330624 83 Linux
#scsi是内核参数
echo '- - -' >/sys/class/scsi_host/host0/scan
[root@compute1 ~]# fdisk -l
Disk /dev/sda: 53.7 GB, 53687091200 bytes, 104857600 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: 0x0009fb23
Device Boot Start End Blocks Id System
/dev/sda1 2048 4196351 2097152 82 Linux swap / Solaris
/dev/sda2 * 4196352 104857599 50330624 83 Linux
Disk /dev/sdb: 10.7 GB, 10737418240 bytes, 20971520 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/sdc: 6442 MB, 6442450944 bytes, 12582912 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