删盘重新扫描设备

背景

业务场景需要，服务器硬盘通道采用jbod模式，经常插拔盘，插盘触发udev挂载脚本，自动挂载路径

问题

NAME MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
sda    8:0    0 931.5G  0 disk /opt/datadisk/10006-1B-B1T-1
sdb    8:16   0   1.8T  0 disk /opt/datadisk/10006-1A-B2T-1
sdc    8:32   0   3.7T  0 disk /opt/datadisk/10062-2A-B4T-1
sdg    8:96   0   1.8T  0 disk /opt/datadisk/10006-2A-B2T-2
sdh    8:112  0 931.5G  0 disk /opt/datadisk/10006-2B-B1T-2
sdi    8:128  0 894.3G  0 disk 
sdk    8:160  0 464.7G  0 disk 
sdl    8:176  0 931.5G  0 disk /opt/datadisk/10062-1B-B1T-1
sdm    8:192  0 931.5G  0 disk /opt/datadisk/10062-2B-B1T-2
sdn    8:208  0   1.8T  0 disk /opt/datadisk/10062-1A-B2T-1
sdo    8:224  0 931.5G  0 disk /opt/datadisk/10061-SL-B1T-1

sdi 没有挂载

步骤

• 确认盘的接口位置

# udevadm info --query=path -n /dev/sdi
/devices/pci0000:00/0000:00:01.0/0000:01:00.0/host0/target0:0:12/0:0:12:0/block/sdi 

确认sdi的接口是host0的target12

H:C:T:L是0:0:12:0

• 从scsi层删除设备映射

# echo 1| sudo tee /sys/class/block/sdi/device/delete 

• 重新扫描设备

# echo "- - -" |sudo tee /sys/class/scsi_host/host0/scan

"- - -"代表channel，target和LUN编号

或者 echo 1 | sudo tee /sys/class/scsi_device/0:0:12:0/device/rescan

• 查看新设备

# lsblk -f
NAME   MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
sda      8:0    0 931.5G  0 disk /opt/datadisk/10006-1B-B1T-1
sdb      8:16   0   1.8T  0 disk /opt/datadisk/10006-1A-B2T-1
sdc      8:32   0   3.7T  0 disk /opt/datadisk/10062-2A-B4T-1
sdg      8:96   0   1.8T  0 disk /opt/datadisk/10006-2A-B2T-2
sdh      8:112  0 931.5G  0 disk /opt/datadisk/10006-2B-B1T-2
sdk      8:160  0 464.7G  0 disk 
├─sdk1   8:161  0    10M  0 part 
├─sdk2   8:162  0     1G  0 part /boot
├─sdk3   8:163  0   128G  0 part /
└─sdk4   8:164  0 335.7G  0 part 
sdl      8:176  0 931.5G  0 disk /opt/datadisk/10062-1B-B1T-1
sdm      8:192  0 931.5G  0 disk /opt/datadisk/10062-2B-B1T-2
sdn      8:208  0   1.8T  0 disk /opt/datadisk/10062-1A-B2T-1
sdo      8:224  0 931.5G  0 disk /opt/datadisk/10061-SL-B1T-1
sdp      8:240  0 894.3G  0 disk /opt/datadisk/10009-X86-B1T-1

sdp就是新的设备