Specifications

Escala Tower PL & S, E, T System Hardware
Chapter 5: Disks and Media 34/62
9es3s1c5.doc
Rev 5.9
02/12/03
The SSA 4-Port Multi-Initiator/RAID EL Adapter allows connection of up to two hosts or nodes. This
enables multiple hosts to access the same data with the high performance and availability features of
SSA.
Note: SSA is a proposed industry-standard interface that retains the SCSI-2 commands, queuing
model, status, and sense bytes.
Characteristics
•
Four SSA ports configurable as two external loops
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Conform to SSA, Level 1
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8-byte bus master
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Address and data parity support
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Streaming data transfer at 40MB/sec or 80MB/sec
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Two-way, high-availability configurations using HACMP Version 4.1 in modes 1, 2, and 3 on AIX
4.1.4
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Support for up to 3,000 I/O operations/sec
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Load balancing on loop configurations
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Attachment of up to 48 SSA disk drives per loop (2-SSA loops per adapter) or a total of 96 SSA
disk drives
•
Micro Channel Type 5 form factor card
An optional
4MB Fast-Write Cache
card is now available and improve write performance in RAID 5
or non-RAID (one-initiator configurations) operations.
The SSA Fast-Write Cache Option Card, FC is a 4 Mbytes fast-write optional feature that will plug
into either SSA Multi-Initiator/RAID EL Adapter. It utilizes non-volatile RAM and has a data memory
retention of over seven years. During the unlikely event of an SSA Multi-Initiator/RAID EL Adapter
failure, a new SSA Multi-Initiator/RAID EL Adapter can be installed and the SSA Fast-Write Cache
Option Card can be removed from the failing adapter and installed in the new SSA Multi-
Initiator/RAID EL Adapter insuring data integrity.
The SSA Fast-Write Cache Option Card can provide as much as a 10-times improvement of data
throughput and response time during certain sequence write operations compared to SSA RAID
adapters without the SSA Fast-Write Cache.
The response time and data transfer improvement using the option card will vary depending upon the
data block sizes, the percentage of sequential writes, machine type/model and application parameters.
The SSA Fast-Write Cache Option Card plugged into either SSA Multi Initiator/RAID EL Adapter
will operate in either Non-RAID or RAID 5 mode, in a one-initiator configuration.
Operational Requirements
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Supported on the Escala E & T except the T610.
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One free PCI slot.
•
Available on the T430 and E230 through reconnection only, when upgrading from the T604e/T620
or E604e/E620 respectively.