热添加了3块20G硬盘，虚拟设备节点：scsi0:2
在系统里面用fdisk -l发现无法找到新添加的3块硬盘
[root@server0 yum.repos.d]# fdisk -l
Disk /dev/sda: 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 label type: dos
Disk identifier: 0x00013f3e
Device Boot Start End Blocks Id System
/dev/sda1 * 2048 20970332 10484142+ 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 label type: dos
Disk identifier: 0x000ad7ac
Device Boot Start End Blocks Id System
/dev/sdb1 2048 1050623 524288 5 Extended
/dev/sdb2 1050624 20971519 9960448 82 Linux swap / Solaris
/dev/sdb5 4096 1050623 523264 82 Linux swap / Solaris
按如下步骤执行：进入到cd /sys/class/scsi_host/
[root@server0 /]# cd /sys/class/scsi_host/
[root@server0 scsi_host]# pwd
/sys/class/scsi_host
[root@server0 scsi_host]# ls
host0 host11 host14 host17 host2 host22 host25 host28 host30 host4 host7
host1 host12 host15 host18 host20 host23 host26 host29 host31 host5 host8
host10 host13 host16 host19 host21 host24 host27 host3 host32 host6 host9
[root@server0 scsi_host]# echo "- - -" > host0/scan #接口扫描新加磁盘即可
[root@server0 scsi_host]# fdisk -l #发现新加磁盘
Disk /dev/sda: 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 label type: dos
Disk identifier: 0x00013f3e
Device Boot Start End Blocks Id System
/dev/sda1 * 2048 20970332 10484142+ 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 label type: dos
Disk identifier: 0x000ad7ac
Device Boot Start End Blocks Id System
/dev/sdb1 2048 1050623 524288 5 Extended
/dev/sdb2 1050624 20971519 9960448 82 Linux swap / Solaris
/dev/sdb5 4096 1050623 523264 82 Linux swap / Solaris
Disk /dev/sdc: 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
Disk /dev/sdd: 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
Disk /dev/sde: 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