The programs included in the package are the ASM (Automatic Storage Management) Dynamic Volume Manager and the ASM Cluster File System. "Cloud FS is a new name for these technologies that are built on ASM," Thome said.
The ASM Cluster File System is a peer-to-peer-based file system that allows users to save material across a range of servers and to access that material from any one of those servers. In addition to being accessed directly through any node on the cluster, data can also be accessed by network file system protocols such as the NFS (Network File System) or Microsoft's CIFS (Common Internet File System).
The file system offers a number of advanced features possibly helpful for the administrator. An advanced permissions system allows administrators to specify when a file can be accessed and with what applications it can be accessed.
Files can also be tagged with attributes, such as the name of the application they are associated with. A user can, for instance, tag all the files that belong to one application and then perform some action against all those files, such as backing them up. "It's almost like a virtual directory, allowing you to perform some type of operation on a set of files that span multiple directories," Thome said.
While the Cluster File System can work as a standalone file system, it can also be overlaid with another file system, such as EXT3, NTFS (Network File System) or ZFS (Zetabyte File System), in order to get the benefits of those file systems as well. Users lose the ability to cluster data across servers with this approach, but still can enjoy other features offered by the Cluster File System.
The ASM Dynamic Volume Manager offers some helpful features as well. It also allows users to add more disks to a system without the need to rebalance data across all the available resources.
"You can grow the file system, shrink it, migrate it from one underlying storage pool to another without any sort of downtime," Thome said. The ASM also produces read-only snapshots of the file system.
