在线添加磁盘，扩展LVM卷案例
一、添加硬盘，在线扫描出来
首先到虚拟机那里添加一块硬盘，注意必须是SCSI类型的硬盘。
扫描硬盘，不用重启操作系统的。 echo "- - -" > /sys/class/scsi_host/host0/scan echo "- - -" > /sys/class/scsi_host/host1/scan echo "- - -" > /sys/class/scsi_host/host2/scan echo "- - -" > /sys/class/scsi_host/host3/scan ....... echo "- - -" > /sys/class/scsi_host/hostn/scan
二、执行fdisk -l 查看扫描出来的新磁盘
root@ceph01:/# fdisk -l Disk /dev/sda: 53.7 GB, 53687091200 bytes 255 heads, 63 sectors/track, 6527 cylinders, total 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 identifier: 0x000a19df Device Boot Start End Blocks Id System /dev/sda1 * 2048 499711 248832 83 Linux /dev/sda2 501758 104855551 52176897 5 Extended /dev/sda5 501760 104855551 52176896 8e Linux LVM Disk /dev/mapper/ceph01--vg-root: 44.8 GB, 44807749632 bytes 255 heads, 63 sectors/track, 5447 cylinders, total 87515136 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 identifier: 0x00000000 Disk /dev/mapper/ceph01--vg-root doesn't contain a valid partition table Disk /dev/mapper/ceph01--vg-swap_1: 8585 MB, 8585740288 bytes 255 heads, 63 sectors/track, 1043 cylinders, total 16769024 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 identifier: 0x00000000 Disk /dev/mapper/ceph01--vg-swap_1 doesn't contain a valid partition table Disk /dev/sdb: 21.5 GB, 21474836480 bytes 255 heads, 63 sectors/track, 2610 cylinders, total 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 identifier: 0x00000000 Disk /dev/sdb doesn't contain a valid partition table root@ceph01:/#