FEC overview

This article is about the frontends supported by the FE group.

Names and subnets

FECs are available in different domain names:

• hostname.acc.gsi.de
• hostnomen.fec.acc.gsi.de
• FEC loads software from asl in the subdirectory with the name 'nomen'.

Example:
If hostname scuxl0815 is mapped to kgp2cu02:

• scuxl0815.acc.gsi.de
• kgp2cu02.fec.acc.gsi.de
• FEC loads software from asl in the subdirectory 'kgp2cu02'.

Hostnames

The IN group supplies frontends with the following hostname conventions.

SCUXLxxxx

• SCU = standard control unit
• X = (64bit system, wanted by m.thieme)
• L = linux
• xxxx = 0001 - 9999

MicroIOCs and in general x86 based FECs

• FELxxxx
• FE = frontend
• L = linux
• MicroIOC if number starts with 9

(if the fecname has "i64" appended, it is a management interface [integrated lights out management = ilo] Ilos are not in their default vlan -> vlan number "64" [which is normal acc net] is appended.)

Access

• All linux tools are working for hostname and nomenclature.
• e.g. ping nomen.fec.acc.gsi.de

Log-in, environment and diagnosis via hostname

There are several comfort functions which support you while working on and with a FEC. -- (will also be implemented to work with the host nomen)

Prerequisites: To benefit from this function the user needs to be in the group "fesa" (type groups in the console to find out, which groups you belong to). Or, if you aren't, just source the needed script with the following command "/common/usr/cscofe/scripts/fesa_uti/fec_access.sh".

How to interact with a FEC the proper way:

• sss [SCU_NUMBER | FEC_NAME]
  
  • logs in as root on scuxlSCU_NUMBER (leading zeros are padded automatically) or FEC_NAME
  • configures the relevant comfort aliases and helper functions
  • runs a short diagnosis
• diag [SCU_NUMBER | FEC_NAME]
  
  • runs a short diagnosis on scuxlSCU_NUMBER (leading zeros are padded automatically) or FEC_NAME

Paswordless login with ssh-key

• generate key-pair for ssh and add the according line to the cscofe script in the export directory (/common/export/cscofe/fe_keys.sh)
• make sure your fec has a symlink to "../global/cscofe" in /common/export/nfsinit/<!FEC>
• reboot the FEC
• start the ssh-agent on the asl cluster and add your key(s) to it:

  eval `ssh-agent -s`; ssh-add

• login to the FEC via ssh/sss
• ask MatthiasWiebel if there are problems

Hostname to hostnomen mapping (FEC DNS mapping)

FEC names are mapped to a nomenclature via a DNS service.

• New mappings can be done via git: https://git.acc.gsi.de/ipam/fec.acc.gsi.de
• Look ups can be done via the tool fec-nomen-lookup:
  • fec-nomen-lookup (FEC_NOMEN | FEC_NAME)

Virtual FECs

See the list of virtual frontends for more information about where to run your mocks.

Access Devices

• Which devices are running on the FEC?: Getting Information from the FESA Database
• How to access them?: Look for dex

Overview of communication paths in SCU

SCU interaction diagram.pdf