High Availability under Linux MT08 EN
From wikitin
Technical thesis title : High_Availability_under_Linux_MT08_EN
Student Lastname: MULLER
Student Firstname: Guillaume
Contents |
Summary
In sectors where the computer network is very important like bank headquarters, companies invest a lot of money to always keep their network and servers constantly available.
High Availability means that the network is unavailable for only 5 minutes per year, including breaks for updating or configuring servers. Linux, a tried and tested Operating System under free license, adds some reliable solutions.
High Availability under Linux is divided into two levels, according to the kind of solutions and the degree of efficiency of Linux products :
Availability of data files
The first level of High Availability: it is in this level that we make sure that data files are never corrupted (RAID), and that data files are secure against human errors (like erasing files).
Availability of services on the computer network
In order to keep the users’ access to the data files and others applications, we must keep access to the network and of course the servers. This access is guaranteed by server redundancy under Linux, with switching to a secondary server in case of failure of the primary server (HeartBeat), or with load balancing between several servers (Linux Virtual Server).
Key words
Hearbeat, LinuxHA, High Availability Linux, DRBD, failover, data files integrity, replication, failover services
Concerned Technologies
Hearbeat, LVS, DRBD, RAID, LVM, CodaFS, GFS
Demonstration
Setting up of two servers (primary and secondary) linked by FailOverServices, with a secure Data Files Server (network and local replication with RAID 1 over IP). When the primary server is down, the secondary will directly replace the primary server and start services.
Illustration
Bibliography
• Haute Disponibilité sous Linux • Wikipédia • CommentCaMarche • RAID • Channel Bonding • Heartbeat • Fake • FailSafe • LVS • Keepalived • LVM • EVMS • DRBD • OpenGFS • InterMezzo • CodaFS • Mon • Livre blanc Alcove sur la Haute Disponibilité • SGI Software Development • Kimberlite
