Question about nfs cluster

Discussion in 'HOWTO-Related Questions' started by Jan VdV, Feb 18, 2007.

  1. Jan VdV

    Jan VdV New Member


    I'm a student and as a graduating project I chose to set up a high availability system with load balancing.
    Two load balancers (one as a backup...) provide connections to two application servers running a webserver, sql and perhaps some other services. These application servers get their content from two data servers running a nfs.

    I followed the howto on setting up a highly available and loadbalanced apache server and the one about a highly available nfs server (both written by Falko Timme). All went well except when rebooting after all was set up, I lost all functionality on the data servers. The screen output was completely messed up, and the system didn't respond anymore until I disabled heartbeat.

    My question is: when BOTH data servers go down, is the nfs lost and if so, why? Is there a solution?

    I've set up my computers in a network lab of my university where also other student are working. There's a good chance at least one of those students will power off my setup and I don't want all my work disappear at the flip of a switch...
  2. falko

    falko Super Moderator ISPConfig Developer

    Does nfs-server get started when the system is booted? Do you see it in the output of
    ps aux
    Any errors in the log files?
  3. Jan VdV

    Jan VdV New Member

    First of all, because of the total loss of the data servers(well, I'm new to all of this, perhaps it could be saved ;-)), I ended up re-installing them. I did not save the error logs so I cannot provide you with that information.

    At the moment the nfs cluster is working like a dream, but I never rebooted both servers at the same time. I only tested if the nfs still worked when one server was down.
    The nfs-server is started at boottime and no errors are generated.

    Since I don't know what the outcome will be, I'm not keen on shutting both of them down.

    But reading between the lines: your answer suggests that the setup should work when both servers go down and are rebooted at the same time?
  4. martinfst

    martinfst ISPConfig Developer ISPConfig Developer

    In general, a cluster configuration should be started one-by-one if both servers went down. It's a bad idea to make both servers fight who's 1st to take precedence.
    I am not familiar with this howto, but as a seasoned sysadmin on linux clusters, thought I'd give you this advise.
  5. Jan VdV

    Jan VdV New Member


    I appreciate your input. Being a student, any information is welcome, especially from experts like you and Mr. Timme.
    I'm going to set a small time delay at boottime on one server to avoid that problem. Hopefully it helps.
  6. falko

    falko Super Moderator ISPConfig Developer

    This is true. If it is possible, don't shut down both servers at the same time.

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