User guide

cluster. A group of computers, linked and working together to form, in some respects, a single computer. The
components of a cluster are usually connected to each other through fast local area networks. Clusters are usually
deployed to achieve better performance, availability, and cost efficiency than a single computer of comparable speed
or availability.
Cluster - Configuration File Creator. A tool run during the configuration of a Microsoft Windows 2008 Cluster
when moving services and applications onto the node.
communications channels. A medium through which a message is transmitted to its intended audience. See also:
v 10 Gb/s LAN
v 100 Mb/s LAN
v DS1
v DS2
v DS3
v OC3
v T1
v T3
consistency group. A consistency group is a set of files that must be backed up/replicated/restored together with
the primary data in order for the application to be properly restored. These groups are used to minimize errors to
maintain data consistency at a recovery site. See cross-consistent replication. See also dependency group.
country code. A two-letter ISO 3166-1 alpha-2 convention uniquely designating a single nation.
credentials. Verifiable names, types, addresses, IDs, passwords, serial numbers, and or licenses that attest the
qualification, competence, authority, or identity of one entity to another, establishing, authenticating, or verifying
legitimacy, intention, purpose, accountability, and trust.
cross-consistent replication. A variety of replication involving a group of servers which preserves their
synchronicity during replication and recovery.
Bytes sent from a client's server must be written to the VSR replication server in the correct order. This is
accomplished by assembling the bytes according to their associated date stamps established by the clock in the client
computer. For normal (non-cross-consistent) replication, each server uses its own clock.
For cross-consistent (group) replication, a group of two or more servers all use the same clock. This ensures that they
will all be precisely synchronized to each other at the time of recovery. All servers in cross-consistent groups must be
physical, because virtual machine clocks can not guarantee the correct time.
Consider the example of a database server and an application server that accesses that database. If they are replicated
as a cross-consistent group, you could be sure that both servers were recovered from exactly the same point in time.
If they were not, however, there would be no guarantee.
Generally, if one recovery protected server requires another recovery protected server to function, they should be
replicated as a cross-consistent group.
CSV. See Comma-separated Values (CSV).
Customer VSR Administrator. Performs any task required of customers role in the IBM SmartCloud VSR service,
including:
v Install a VSR Replication Client
– Install a VSR Replication Client (Windows 2003 or 2008)
– Install Red Hat 5 Linux Replication Client
v Create a Site/Location
v Delete a Site/Location
v Set Site Options
v Set Site Options and Server Groups
v Add Servers to the Solution
– Add a Server (with No Cross-consistency)
– Add a Server (with Cross-consistency)
74 IBM SmartCloud Virtualized Server Recovery: Customer User Guide