Oracle Linux Tips


Serial Console

# cat /etc/default/grub
GRUB_TIMEOUT=5
GRUB_DISTRIBUTOR="$(sed 's, release .*$,,g' /etc/system-release)"
GRUB_DEFAULT=saved
GRUB_DISABLE_SUBMENU=true
GRUB_TERMINAL="console serial"
GRUB_SERIAL_COMMAND="serial --speed=115200 --unit=0 --word=8 --parity=no --stop=1"
GRUB_CMDLINE_LINUX="crashkernel=auto rd.lvm.lv=ol/root"
GRUB_CMDLINE_LINUX_DEFAULT="console=ttyS0,115200"
GRUB_DISABLE_RECOVERY="true"

# grub2-mkconfig -o /boot/grub2/grub.cfg


# cat /etc/default/grub
GRUB_TIMEOUT=5
GRUB_DISTRIBUTOR="$(sed 's, release .*$,,g' /etc/system-release)"
GRUB_DEFAULT=saved
GRUB_DISABLE_SUBMENU=true
GRUB_TERMINAL="console serial"
GRUB_SERIAL_COMMAND="serial --speed=115200 --unit=0 --word=8 --parity=no --stop=1"
GRUB_CMDLINE_LINUX="crashkernel=auto rd.lvm.lv=ol/root rd.lvm.lv=ol/swap"
GRUB_CMDLINE_LINUX_DEFAULT="console=ttyS0,115200"
GRUB_DISABLE_RECOVERY="true"

# for f in /boot/vm*; do grubby --info $f; done
# for f in /boot/vm*; do grubby --remove-args="rhgb quiet" --args="console=ttyS0,115200" --update-kernel=$f; done
# for f in /boot/vm*; do grubby --info $f; done
# grub2-mkconfig -o /boot/efi/EFI/*/grub.cfg

iSCSI Initiator

  1. Install the package
    # dnf install iscsi-initiator-utils
  2. Discover targets
    # iscsiadm -m discovery -t sendtargets -p SCSI_TARGET_SERVER
  3. Display target information
    # iscsiadm -m discoverydb -t st -p SCSI_TARGET_SERVER
  4. Establish a session
    # iscsiadm -m node -T iqn.XXX... -p SCSI_TARGET_SERVER:3260 -l
  5. Verify session
    # iscsiadm -m session -P 3
  6. When adding an iSCSI LUN to the fstab, use the _netdev option
    UUID=xxx... /MP ext4 _netdev 0 0
  7. Log out of session
    # iscsiadm -m node -T iqn.XXX... -p SCSI_TARGET_SERVER:3260 --logout
  8. Remove target from database
    # iscsiadm -m node -T iqn.XXX... -p SCSI_TARGET_SERVER:3260 -o delete
  9. If target server has gone away, entries can be removed manually
    # rm -rf /var/lib/iscsi/nodes/TARGET