IBM System Storage DS4000, Руководство по оборудованию

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Chapter 3. IBM System Storage DS4000 and DS5000 hardware
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򐂰 FlashCopy (premium feature) for up to 16 copies per base volume. There are two
FlashCopies per default (without premium feature).
򐂰 VolumeCopy (premium feature).
򐂰
Remote Volume Mirroring: Metro Mirror, Global Mirror, and Global Copy (premium
features) for up to 128 pairs.
򐂰 Standard DB-9 serial connection for service purposes.
Additionally, the DS5100 offers further value in flexibility, scalability, and investment protection
by providing the ability to upgrade to a DS5300. The DS5100 provides excellent performance
for dynamic storage consolidation solutions in the deployment stage, with the full assurance
that this model can be upgraded to a DS5300 performance level if required.
3.4.1 DS5100 and DS5300 controller architecture
The DS5100 uses the same hardware as the DS5300, although the internal bus speed is
reduced by the controller code (controller firmware). Both use two controllers connected by
the interconnect module. It does not have a backplane board.
This section describes the architecture of a single controller. The DS5300 controller uses a
seventh generation dedicated ZIP application-specific integrated circuit (ASIC) chip, which is
designed and customized for a particular use, rather than intended for general purpose use.
The new ZIP ASIC is designed for supporting I/O operations, especially for calculating
redundancy information for RAID 3, RAID 5, and RAID 6. The parity can be calculated much
faster by dedicated hardware than by software, which results in good performance, especially
for writing data that is protected by one of the mentioned RAID levels.
The ZIP ASIC chip calculates data in cache, so it uses a fast 17 Gbps bus to cache memory
dedicated for data. The DS5300 controller is based on a PCI Express x8 2 Gbps architecture.
With the ZIP ASIC, there is also an Intel Xeon® 2.8 GHz processor with dedicated 2 GB of
memory for I/O control, management, and other general purposes. The ZIP ASIC chip is one
of the most important components in the architecture, so all disk and host chips are directly
connected using fast PCI Express buses to achieve high performance.
There are two quad FC 4 Gb chips dedicated to disk channels connected to the ASIC through
two PCI Express buses. The first chip is connected to eight external FC 4 Gbit ports through
internal switches in the same controller. The second one is connected to eight external FC 4
Gb ports in the second controller through interconnect modules. Internal switches are used to
have a non-blocking connection to each disk channel port from both controllers.
The ZIP ASIC is connected through two PCI Express buses to two Host Interface Cards.
Each card has four FC 4 Gb ports.
DS5300 uses two dedicated PCI Express buses for mirroring the cache. The buses connect
directly to the ASICs on both controllers through the interconnect module.