Novell LINUX ENTERPRISE SERVER 10 - INSTALLATION AND ADMINISTRATION 04-08-2006 Installation Manual page 274

12.4.2 RAID
RAID (redundant array of independent disks) brings together several hard disk partitions
to form a large virtual hard disk. RAID can be used to optimize the performance and
data security of your system. RAID levels 1 and 5 offer protection against the failure
of a disk because the data is recorded on several disks at the same time. This ensures
that the complete data record is always available on another disk in the system should
a disk fail. Find more information about RAID with SUSE® Linux Enterprise Server
in Section 6.2, "Soft RAID Configuration" (page 131).
12.4.3 rsync
rsync can be used to synchronize large amounts of data between a server and its backup.
rsync has sophisticated mechanisms for only transferring changes to files. This applies
not only to text files, but also to binary files. To enable the differences between files
to be identified, rsync divides the files into blocks and calculates checksums for these
blocks. Find more information about rsync in Section 40.6, "Introduction to rsync"
(page 744).
12.4.4 DRBD
Distributed replicated block device (drbd) mirrors (RAID1) partitions and logical vol-
umes (data areas) by means of a normal network on the basis of TCP/IP. Each node
has a particular drbd resource active and all changes are mirrored as secure transactions.
drbd has additional features in comparison with RAID1 for local disks that enable the
resynchronization time to be minimized after the two nodes have been disconnected
briefly and a robust check after various malfunctions to establish which side has the
latest, consistent data.
274 Installation and Administration