Admin notes

Instruction on how to connect iSCSI on the server

Install packages: yum install -y libiscsi-utils iscsi-initiator-utils device-mapper-multipath
On the server, change the iSCSI ID: iscsi-iname -p SERVER_NAME, the obtained string is written in the file /etc/iscsi/initiatorname.iscsi
Restart iscsi (if it did not start because of “not fulfilled conditions”, it will be fine)
Execute iscsiadm --mode discovery --type sendtargets --portal STORAGE_IP --login (STORAGE_IP from Manage network).
Go to the storage interface, under Hosts/initiators, our host’s name should appear.
In this same interface, create a “host”, specify the name, IP address, and in the list of initiators should be one with our iSCSI-ID, select it.
On the storage, create luns or groups of luns (optional)
Assign access to our host for created or previously existing groups of luns (or individual luns).
On the server, execute rescan-scsi-bus.sh from sg3_utils, all luns should appear.
Create a configuration for multipath: mpathconf --enable.
In most cases, the default configuration works. To exclude some luns/disks, write them in the section blacklist.
Start the service: systemctl enable multipathd; systemctl start multipathd
Now execute multipath -ll and see all devices from mapper-а (mpathXX)

If something went wrong:

Logout from host: iscsiadm -m node -u
Re-login: iscsiadm --mode discovery --type sendtargets --portal STORAGE_IP --login