Explanations |
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EXTENDED
COPY
ENHANCED COPY
XCOPY |
SCSI-3
block copy command, also known as third-party copy. |
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FC-AL
Fibre Channel Arbitrated Loop |
A
reference to the Fibre Channel Arbitrated Loop standard, a shared
gigabit media for up to 127 nodes, one of which may be attached
to a switch fabric. |
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FC-TAPE
Fibre Channel Tape
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FC-TAPE
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HA
High Availability |
To
provide a truly robust HA system, continuous access to the data
storage system must be provided. In a high availability design,
uninterrupted access to all connected nodes are a primary objective.
To achieve this, multiple SAN connections need to be incorporated
to provide alternate network paths, eliminating any potential SPOF
(single points of failure). Duplication or mirroring of key SAN
components such as switches and cabling is necessary in a HA design.
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NDMP
Network Data Management Protocol |
An
open standard protocol for enterprise-wide backup of heterogeneous
network-attached storage. NDMP was co-invented by Network Appliance
and PDC Software (now part of Legato Systems, Inc.). In April 2000,
a new work group for NDMP was formed as part of SNIA. The new group
will be responsible for the development of the protocol standard,
interoperability testing, and educational programs for NDMP.
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RTO
Recovery Time Objective |
The
level of HA provided in any SAN design is determined by the Recovery
Time Objective (RTO) - this is the time needed to recover from a
disaster, a business driven analysis that is determined by the acceptable
time period to be without online systems pending a hardware failure.
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RPO
Recovery Point Objective |
The
Recovery Point Objective describes the age of the data you require
the ability to restore in the event of a disaster. For example,
if your RPO were 6 hours, it would mean you want to be able to
restore systems back to the state they were in, as of no longer
than 6 hours ago. To achieve this, you need to be making backups
or other data copies at least every 6 hours. Any data created
or modified inside your recovery point objective will be either
lost or must be recreated during a recovery. If your RPO is that
no data is lost, synchronous remote copy solutions are your only
choice.
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Copyright
1998-2003 StorageWorld - Discovery Business Systems Ltd
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