Environment introduction:
Modify the configuration based on the ISCSI service to realize the Multipath environment
Server eth0:192.168.4.101 Client eth0:192.168.4.102 in ISCSI service configuration
In Multipath, you need to add another network card eth1 to the Server and Client
Server eth1:192.168.2.101 Client eth0:192.168.2.102
1. Modify the ISCSI ACL configuration on the server side and increase the permission of 192.168.2.102
[root@node1 ~]# tail -5 /etc/tgt/targets.conf <target iqn.2018-04.com.example.node1:server.target1> backing-store /dev/sda1 initiator-address 192.168.4.102 initiator-address 192.168.2.102 </target>
2. The client discovers the server share through 192.169.2.101
[root@node2 ~]# iscsiadm --mode discoverydb --type sendtargets --portal 192.168.2.101 --discover
3. Restart the ISCSI service and find that there are two paths connected to the shared storage of the Server
[root@node2 ~]# /etc/init.d/iscsi restart stop iscsi: [OK] Starting iscsi: [OK] [root@node2 ~]# lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT sr0 11: 0 1 1024M 0 rom vda 252:0 0 50G 0 disk ├─vda1 252:1 0 500M 0 part /boot └─vda2 252:2 0 49.5G 0 part Ol─VolGroup-lv_root (dm-0) 253: 0 0 47.6G 0 lvm / └─VolGroup-lv_swap (dm-1) 253:1 0 2G 0 lvm [SWAP] sdb 8:16 0 20G 0 disk └─sdb1 8:17 0 976M 0 part sdc 8:32 0 20G 0 disk └─sdc1 8:33 0 976M 0 part
4. Install device-mapper-multipath
[root@node2 ~]# yum -y install device-mapper-multipath
5. Turn off the automatic naming function for shared storage and generate a configuration file
[root@node2 ~]# mpathconf --user_friendly_names n [root@node2 ~]# ls /etc/multipath.conf /etc/multipath.conf
6. Check the wwid of the connected shared device and confirm that the two target storage devices for multipathing are the same device
[root@node2 ~]# /lib/udev/scsi_id --whitelisted --device=/dev/sdb 1IET 00010001 [root@node2 ~]# /lib/udev/scsi_id --whitelisted --device=/dev/sdc 1IET 00010001
7. Modify the configuration file and start the service
[root@node2 ~]# sed -n '25,28p;102,107p' /etc/multipath.conf
defaults {
user_friendly_names no
getuid_callout "/lib/udev/scsi_id --whitelisted --device=/dev/%n"
}
multipaths {
multipath {
wwid "1IET 00010001"
alias mpa
}
}
[root@node2 ~]# /etc/init.d/multipathd start;chkconfig multipathd on
[root@node2 ~]# ls /dev/mapper/ ##View the aliases of Multipath shared devices control mpa mpap1 VolGroup-lv_root VolGroup-lv_swap
8. Restart the ISCSI service to check the disk status
[root@node2 ~]# /etc/init.d/iscsi restar stop iscsi: [OK] Starting iscsi: [OK] [root@node2 ~]# lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT sr0 11: 0 1 1024M 0 rom vda 252:0 0 50G 0 disk ├─vda1 252:1 0 500M 0 part /boot └─vda2 252:2 0 49.5G 0 part Ol─VolGroup-lv_root (dm-0) 253: 0 0 47.6G 0 lvm / └─VolGroup-lv_swap (dm-1) 253:1 0 2G 0 lvm [SWAP] sdc 8:32 0 20G 0 disk └─mpa (dm-2) 253:2 0 20G 0 mpath └─mpap1 (dm-3) 253:3 0 976M 0 part /var/lib/mysql sdb 8:16 0 20G 0 disk └─mpa (dm-2) 253:2 0 20G 0 mpath └─mpap1 (dm-3) 253:3 0 976M 0 part /var/lib/mysql
9. Mount the Multipath shared storage to the mysql application data directory, or write the mounting work to /etc/fstab to achieve automatic mounting at startup
[root@node2 ~]# mount /dev/mapper/mpap1 /var/lib/mysql/