February 17, 2019

Using the InterMezzo Distributed Filesystem - page 7

Getting Connected in a Disconnected World

  • August 12, 2002
  • By Bill von Hagen

First, you must create or identify the journaling filesystem that will hold the InterMezzo data that you plan to export from the server. This section uses an ext3 filesystem as an example, though you can also use any journaling filesystem or even an ext2 filesystem in a pinch. Using an ext2 filesystem is not as robust as using a journaling filesystem because it increases the possibility that InterMezzo synchronization data and log information may be lost if you system crashes.

If you have a free ext3 partition that you want to use for InterMezzo, skip to the next paragraph. If not, create an ext3 filesystem on an unused partition by executing the command mke2fs -t ext3 partition-name, where partition-name is the name of your partition.

Next, create the mount point for the InterMezzo filesystem using the command mkdir -p /exports/server. This can be anywhere, but /exports/server is the most commonly-used location. After creating the mount point, mount the InterMezzo filesystem using the command mount -t intermezzo partition-name /exports/server. For the purposes of this article, change the mode of the root of the filesystem to 777 (making it publicly writable) by using the command chmod 4777 /exports/server. You would not want to do this in most production environments.

If you are going to be experimenting with InterMezzo for a while, you should add an appropriate entry for this filesystem to the end of your systems /etc/fstab file so that your system automatically mounts this filesystem each time it boots.

Next, start the InterSync synchronization server using the command intersync /exports/server&. You should then copy some sample file(s) and/or directories into this filesystem, so that you can verify that things are working once you start your client system, as described in the next section.

If you installed InterSync on a Red Hat system from the RPM described earlier in this article, a startup file for InterSync was installed in your system's startup directory. On InterMezzo server systems, you can automatically start InterSync (and load the InterMezzo loadable kernel module) each time you boot your system by creating a symbolic link to the file /etc/rc.d/init.d/intersync in the startup directory for your system's default run level (which is listed in the file /etc/inittab). This file was created automatically if you installed InterSync from the RPM package described earlier in this article. For example, on a Red Hat Linux system that starts run level 5 by default, you could do this by creating a symbolic link named /etc/rc.d/rc5.d/S99intersync that points to this file.

Before attempting to automatically start InterMezzo on server systems, you must edit the file /etc/rc.d/init.d/intersync and supply a correct values for the CACHE environment variable. Though something of a misnomer, on server systems the CACHE variable should contain the InterMezzo directory that your server is exporting, which would be /exports/server if you followed the suggestions given in this section.

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