Products

Storage Area Network

Ubuntu Server Edition 8.04 brings the power of inexpensive shared storage to your servers. More and more organizations rely on the throughput of Ethernet Gigabit or 10 Gibabit to build up their SAN (storage area network), whether they use it for data or virtual machine storage. Using relatively inexpensive hardware, the performances can be quite amazing.

Three tehnologies are now supported in Ubuntu Server Edition 8.04: iSCSI and DRBD. Being low level protocols, users still have the choice of the file system type they use on top of them, and thus determine if they need concurent access or not. Concurrent acces is generally carried using GFS2 or OCFS2. It is, in every case, possible to use LVM2 in between as their volume management system.

iSCSI

iSCSI is implemented by many storage vendor equipment that Ubuntu can now easily connect to. iSCSI has also been implemented within the installer so that it is now possible to directly install to an iSCSI device, which is particularly useful when using virtualization to consolidate servers. iSCSI is also commonly used to build clusters, shared access or backup. Given the capacity of TCP/IP to be routed, it is also used in disaster recovery scenarios to copy volumes over long distances. Ubuntu Server Edition acts as an iSCSI software initiator using the open-iscsi package. Additionally the server can be installed and booted directly from the an iSCSI SAN device.

DRBD

DRBD is a very low cost replicated block device that can be used to create high availability clusters. DRDB does not require any additional equipment to store the data, as it is used to mirror data (at device level) in between multiple computers via the network. DRBD is generally used in 2 node clusters with a maximum of eight nodes, and since version 8, can be used for concurent access from the two nodes using file systems such as GFS2 or OCFS2. It uses the drdb8 kernel module.