Achieving Robust Clustered Storage with Linux and GFS

[from http://www.enterprisestorageforum.com]

Load balancing is difficult. We often we need to share file systems via NFS or other mechanisms to provide a central location for the data. While you may be protected against a Web server node failure, you are still sharing fate with the central storage node.

Using GFS, the free clustered file system in Linux, you can create a truly robust cluster that does not depend on other servers. In this article, we'll show you how to properly configure GFS.

Conceptually, a clustered file system allows multiple operating systems to mount the same file system and write to it at the same time. There are many clustered file systems available, including Sun's (NASDAQ: JAVA) Lustre, OCFS from Oracle (NASDAQ: ORCL), and GFS for Linux.

There are a few methods by which a block device can be made available on multiple servers at once. You can zone a SAN LUN to be visible to multiple servers, configure iSCSI to do the same, or use DRBD to replicate a partition between two servers. With DRBD, you will need to configure it in Primary/Primary mode to use GFS.

Read more at ... http://www.enterprisestorageforum.com/sans/features/article.php/3824876