Installation
DataDirect Networks S2A 9550 User Guide
19
2.3
Configuring the S2A9550
This section provides information on configuring your S2A9550.
NOTE :
The configuration examples provided in this section represents a general
guideline and should not be used directly to configure your particular S2
A9550
. The
CLI commands used in these examples are fully documented in Sections 3.1 to 3.8,
though exact commands may change depending on your firmware version. To access the
most up-to-date commands, use the online HELP feature.
2.3.1
Setup Planning
The S2A9550 offers great flexibility in defining LUN configurations and optimizing
performance for specific applications. Before proceeding with your S2A9550
configuration, it is necessary to determine the requirements for your SAN environment,
including the types of I/O access (random or sequential), the number of storage arrays
(LUNs) and their sizes, and user access rights.
The Silicon Storage Appliance provides a patent-pending, fully parallelized, distributed,
and multi-tasking hardware RAID implementation that uses a 8+1+1 parity scheme called
directRAID
. It is a unique implementation that combines the virtues of RAID 3, RAID 5
and RAID 0
. Like RAID 3, a dedicated parity drive is used per (8+1) parity
group, called a “Tier”. directRAID exhibits RAID 3 characteristics such as tremendous
large block-transfer—READ and WRITE—capability with NO performance degradation
in crippled mode.
Like RAID 5, however, directRAID does not lock drive spindles and does allow the disks
to re-order commands to minimize seek latency, and the RAID 0-like functionality allows
multiple Tiers to be striped, providing “PowerLUNs” that can span 100’s of disk drives.
These PowerLUNs support very high throughput and a greatly enhanced ability to handle
small I/O (particularly as disk spindles are added) and many, many streams of real-time
content.
LUNs can be created on a fraction of a Tier, a full Tier, across a fraction of multiple Tiers,
or across multiple full Tiers. Tiers of drives are added 9 drives (8+1) at a time, with an
arbitrary number of hot spares (up to 125) supported. A tenth loop is utilized for the spare
disks (8+1+1). Up to 125 Tiers may be utilized, but the current SF4016 enclosure
(supplied by DDN), limits the number of Tiers to 120 (due to the Fibre-Channel ID
numbering scheme in the enclosure itself). When using SF2016 enclosures, this number
is limited to 112.
Tier Configuration
Space Available
(Mbytes)
Tier
Disk Status
Lun List
Capacity
(Mbytes)
ABCDEFGHPS
------------------------------------------------------------
271820
280012
1
ABCDEFGHPS
271820
280012
2
ABCDEFGHPS
271820
280012
3
Figure 2-4 Striping Across Tiers - directRAID
0
0
0
---------------->
Parity Protection within same tier
---
-------->
Striping
across tiers
when a LUN
is created
across
multiple tiers
Summary of Contents for S2A9550
Page 1: ...DataDirect Networks Silicon Storage Appliance S2A9550 User Guide Rev 4 0 ...
Page 13: ...SECTION 1 Introducing the S2A9550 ...
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Page 21: ...SECTION 2 Installing the S2A9550 ...
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Page 43: ...SECTION 3 Using the S2A9550 Management Administrative Facilities ...
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Page 93: ...SECTION 4 Supporting the S2A9550 ...
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Page 113: ...SECTION 5 Appendices ...