Neil H Watson, Linux consultant

In this part of the series we will learn how to make a service run on an IPV6 address.

The first step in my exploration of IPV6 was to get an IPV6 address via an IPV4 to IPV6 tunnel. A little research lead me to the fine folks at SixXS.

Contents

• Overview
  • What is Cfengine?
  • Client/Server architecture
  • Directories and files
  
  
• Basic example
  • Installation
  • Initial setup
  
  
• Other examples
  • Editing files
  • Disabling files
  • Disabling processes
  
  
• Further reading

1. Format and mount the SAN LUN.
2. Start a write to the mounted filesystem cat /dev/zero >> /pathto/mnt/testfile &
3. Now connect to the multipath daemon in interactive mode multipathd -k
4. View current paths with show maps topology

   multipathd> show maps topology
   reload: mpath5 (360060e801045249004f2a5f900000031) dm-7 HITACHI,DF600F
   [size=128G][features=0][hwhandler=0][rw]
   \_ round-robin 0 [prio=1][active]
    \_ 1:0:0:4 sdb 8:16  [active][ready]
   \_ round-robin 0 [prio=0][enabled]
    \_ 2:0:0:4 sdc 8:32  [active][ready]
   

5. There are two paths shown as sdb and sdc. Delete one path.
   del path sdb
6. Suspend with ctrl-z and check that the write is still happening.
   ls -l /pathto/mnt If testfile is still growing then the path sdc is working.
7. Resume multipath with fg 2. Re-add the path.
   add path sdb
8. Now remove the other path.
   del path sdc
9. Again suspend iwth ctrl-z and check that the test file is growing. If so then resume multipath and re-add the path.
   add path sdc
10. Testing complete. Exit with ctrl-c. Kill the write job with kill %1. Remove the test file.

Linux Ethernet bonding

# Loading module:
# for Red Hat AS4, may work with other 2.6 Linuxes.
install bond0 /sbin/modprobe bonding -o bond0 mode=0 miimon=100
# for Red Hat AS3, may work with other 2.4 Linuxes.
alias bond0 bonding
options bond0 -o bonding mode=0 miimon=100
# For Redhat distributions
# ifcfg-ethx
DEVICE=ethx
USERCTL=no
ONBOOT=yes
MASTER=bond0
SLAVE=yes
BOOTPROTO=none

# ifcfg-bond0
DEVICE=bond0
USERCTL=no
ONBOOT=yes
IPADDR=172.16.48.66
NETMASK=255.255.255.0
GATEWAY=172.16.48.1

OSI model diagram

This entry offers solutions to system administration problems using the configuration management tool Cfengine 2. Cookbook now available for Cfengine 3.

This entry presents an overview of how to build a DB2 service cluster using the Red Hat Cluster Suite. This procedure can be useful in learning how to setup clusters for other services.