Wednesday, April 05, 2017

todays random thoughts

As I write this my home server is down; I was learning glusterfs when I accidentally rebooted the Xen server which was holding all my virtual machines.  It has been a few minutes; it is unusual so the server may have crashed already.

Anyhow--

Today's lesson is: FIX HOSTNAMES FIRST before setting up glusterfs.  Glusterfs needs a good working hostname resolution in order to work.  Gluster is miserable with a broken DNS.

It also does not help that somewhere along the line, something, or somebody (*cough* ISP *cough*) modifies the dns queries that returns some far-off IP addresses on failed resolution.

Specifically make sure these work and actually point to your servers:

       node-testing-1.yoursubdomain.domain.net
       node-testing-2.yoursubdomain.domain.net
       node-testing-3.yoursubdomain.domain.net
       node-client-test.yoursubdomain.domain.net

ALSO make sure these work and actually point your servers (this is the part that someting in the dns query path might return some random IP address making the gluster server contact some unknown far-off host):

      node-testing-1
      node-testing-2
      node-testing-3
      node-client-test

The way I did this was put "yoursubdomain.domain.net" in the "search" parameter of /etc/resolv.conf.  Others will probably just put the entries in /etc/hosts.  Whatever works. 

By the way, configuring the search parameter on resolv.conf differs between debian and redhat-derived distributions.  For deiban-derived it is best to install "resolvconf" and put a keyword in /etc/network/interfaces; for redhat-derived it is easer to just use "nmtui" or put a keyword in /etc/sysconfig/network-scripts/whatever/ifcfg-whatever

My server is back online...thank you for reading this.

JondZ 20170505

Creating ipip tunnels in RedHat 8 that is compatible with LVS/TUN. Every few seasons I built a virtual LVS (Linux Virtual Server) mock up ju...