RH299CourseNotesDay3

iSCSI

Workbook 2, chapter 6 (providing remote block storage), page 145.

A quick Google yields https://www.thomas-krenn.com/en/wiki/ISCSI_Basics and man iscsiadm.

1. Target iSCSI server
2. Initiator iSCSI client
3. Node server
4. iQN iqn.YYYY-MM.com.reversed.server.fqdn:optional_name
5. ACL uses iQN
6. LUN - Logical Unit Number
7. Portal 172.25.0.11 eth0 eth1 eth3
8. Discovery
9. iscsiadm -m discovery -t send_targets -p 10.10.10.10 @salikov example

Login

• iSCSI still uses CDB (Command Descriptor Block) command set originally defined by the original SCSI standards.

iSCSI Server

• yum install targetcli

[root@server9:~] $ targetcli
/> ls

• firewall-cmd --add-port=3260/tcp
• firewall-cmd --add-port=3260/tcp --permanent
• systemctl endable target
• systemctl start target

iSCSI Client

• yum install iscsi-initiator-utils

• echo "InitiatorName=iqn.2016-09.com.example.desktop9:optional_name" > /etc/iscsi/initiatorname.iscsi

  • systemctl restart iscsid` - only necessary if you changed the initiator name after doing a scan
  • systemctl restart iscsi`

• iscsiadm -m discovery -t st -p 172.25.N.11

  • Caches persistently into /var/lib/iscsi/nodes/

• iscsiadm -m node -T iqn.2016-09.com.example.server9:optional_name -p 172.25.N.11 -l to login to tagret iQN at portal address

• iscsiadm -m session to show establisted iSCSI sessions

• lsblk -o +UUID to show the new block device (check under /sys/block/)

• Partition and format the new block device.

• Add filesystem using UUID to /etc/fstab.

• You can logout and remove the iSCSI disk permanently if you wish using iscsiadm -m node -T iqn.2016-09.com.example.server9:optional_name -p 172.25.N.11 -o delete

NetworkMangler

Workbook 2, chapter 1 (managing ipv6 networking), page 1.

• Relies on NetworkManager systemd service.
• nmcli, nmtui, nm*
• /etc/sysconfig/network-scripts/ifcfg-*
• /etc/NetworkManager
• hostnamectl

Postfix

Workbook 2, chapter 5 (configuring email transmission), page 134.

• postconf -e "local_transmission=error: local delivery disabled"
• postconf -e "relayhost=smtpX.example.com"
• postconf -e "inet_interfaces=loopback-only"
• postconf -e "mynetworks="127.0.0.1/8 [::1]/128"
• postconf -e "myorigin=desktopX.example.com"
• postconf -e "mydestination="
• systemctl restart postfix