User guide

© 2011 Cisco Systems, Inc. All rights reserved. This document is Cisco Public Information. Cisco Validated Design Page 79
Figure 43. NetApp Fibre Channel target ports
5.5.1 Boot From SAN
Booting from SAN is another critical feature which helps in moving towards stateless computing in which there is
no static binding between a physical server and the OS / applications it is supposed to run. The OS is installed on
a SAN lun and boot from SAN policy is applied to the service profile template or the service profile. If the service
profile were to be moved to another server, the pwwn of the HBAs and the BFS policy also moves along with it.
The new server now takes the same exact view of the old server, the true stateless nature of the blade server.
The main benefits of booting from the network:
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Reduce Server Footprints: Boot from SAN alleviates the necessity for each server to have its own direct-
attached disk, eliminating internal disks as a potential point of failure. Thin diskless servers also take up
less facility space, require less power, and are generally less expensive because they have fewer hardware
components.
●
Disaster and Server Failure Recovery: All the boot information and production data stored on a local SAN
can be replicated to a SAN at a remote disaster recovery site. If a disaster destroys functionality of the
servers at the primary site, the remote site can take over with minimal downtime.
Recovery from server failures is simplified in a SAN environment. With the help of snapshots, mirrors of a
failed server can be recovered quickly by booting from the original copy of its image. As a result, boot from
SAN can greatly reduce the time required for server recovery.