RH299CourseNotesDay3

29th September 2016 at 5:19pm
RH299CourseNotes

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
    1. iscsiadm -m discovery -t send_targets -p 10.10.10.10 @salikov example
  9. 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

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