EMC announced several enhancements to its Symmetrix 8000 family of storage subsystems, and enhancements to its SRDF and TimeFinder products.
- Three new Symmetrix models (8230, 8530 and 8830)
- More and faster PowerPC microprocessors
- Up to 69.5TB raw capacity (34.7TB in RAID-1)
- Up to 8,000 logical volumes
- Up to 64GB of cache
- 4 port and 12 port Fibre Channel Directors
- Increased number of concurrent ESCON I/Os to 32
- Increased number of ESCON logical paths per port to 512
- Dynamic PAV/MA support
- Increased number of hypervolumes per physical disk device to 128
- RAID-10 for z/OS (OS/390)
- FICON Channel Director scheduled for general availability in first quarter 2002
- GDPS support with native PPRC compatibility scheduled for general availability in first quarter 2002
New Symmetrix modelsThe currently available members of the Symmetrix 8000 family will now consist of three models: the 8230, 8530 and 8830. The 8230 is a new entry-level model. The 8530 replaces the 8430, and the 8830 replaces the 8730.
The new 8230 is EMC's entry-level model. The 8230 consists of two channel directors, up to forty-eight disk devices with up to 3.5TB of raw capacity,
- Up to 48 36GB/73GB disk devices
- Up to 3.5TB raw capacity (1.7TB RAID-1)
- Up to 32 GB of cache
- Up to 24 Fibre Channel connections
- Up to 8 Ultra/Ultra2 SCSI connections
- Up to 8 ESCON connections and concurrent I/Os
- Up to 4 FICON connections (GA 1Q02)
The 8530 is an enhanced version of the 8430. It can consist of up to six channel directors, up to ninety-six disk devices with up 17.4TB of raw capacity, and up to 64GB of cache.
- Up to 96 36GB/73GB/181GB disk devices
- Up to 17.3TB raw capacity (8.7TB RAID-1)
- Up to 64GB of cache
- Up to 72 Fibre Channel connections
- Up to 24 Ultra/Ultra2 SCSI connections
- Up to 24 ESCON connections and concurrent I/Os
- Up to 12 FICON connections (GA 1Q02)
The 8830 is an enhanced version of the 8730. It can consist of up to eight channel directors, up to 384 disk devices with up to 69.5TB of raw capacity, and up to 64GB of cache.
- Up to 384 36GB/73GB/181GB disk devices
- Up to 69.5TB raw capacity (34.7TB RAID-1)
- Up to 64GB of cache
- Up to 96 Fibre Channel connections
- Up to 32 Ultra/Ultra2 SCSI connections
- Up to 32 ESCON connections and concurrent I/Os
- Up to 16 FICON connections (GA 1Q02)
The number of microprocessors was increased in the new models, and they were upgraded to the 333MHz PowerPC versus the 266MHz versions in the previous models. Refer to Table 1 for detailed comparisons of the microprocessors.
The capacity increase available with the 8830 was enabled with the increase in the number of hypervolumes per physical disk device to 128, and the number of logical volumes to 8,000.
The capacity configuration capabilities of the Symmetrix, like the rest of the cache centric subsystems (Amdahl Platinum/400, Hitachi 9900, IBM 2305 ESS, and StorageTek V960) are limited by the characteristics of 3990/3390 subsystems upon which they are based. For example, the 8830 (and 8730) can contain up to 384 181GB disk devices. This provides a raw disk capacity of up to 69.5TB. However, with the previous maximum of 4,096 logical volumes, and assuming 3390-9 emulation (8.514GB per volume), the maximum usable capacity was only 34.816TB. By supporting up to 8,000 logical 3390-9 volumes, the maximum usable capacity has been increased to 69.5TBs. However, there will be configuration limitations with ESCON connections due to ESCON's inherent support of just 4,096 logical volumes. Refer to Table 1 for detailed comparisons of the capacity options.
The specifications for the 8230 and a comparison of the specifications for the 8430/8530 and 8730/8830 are provided in Table 1.
|- Number of disk directors||2||4||4||8||8|
|- Number of devices||4 to 8||8 to 96||8 to 96||32 to 384||32 to 384|
|- Type (GB capacity)||36/73||36/73/181||36/73/181||36/73/181||36/73/181|
|Usable Storage Capacity (GBs)|
|- RAID-1||72 to 1,754||143 to 8,688||143 to 8,688||572 to 34,752||572 to 34,752|
|- RAID-S (36GB only)||107 to 1,300||214 to 2,606||214 to 2,606||859 to 10,425||859 to 10,425|
|- SRDF||144 to 3,464||286 to 17,376||286 to 17,376||1,145 to 34,752||1,145 to 69,504|
|- Number cache boards||2||4 or 2*||4 or 2*||4||4|
|- GBs of cache||32||32 or 16*||64 or 32*||32||64|
|Number Channel Directors||2||2 to 4 or 6*||2 to 4 or 6*||2 to 8||2 to 8|
|- ESCON 4-port||8||8 to 24*||8 to 24*||4 to 16||8 to 32|
|- FICON 2-port||4||N/A||N/A||N/A||N/A|
|- SCSI 4-port||8||8 to 24*||8 to 24*||8 to 32||8 to 32|
|- 2-port director||4||4 to 12*||4 to 12*||4 to 16||4 to 16|
|- 4-port director||8||8 to 24*||8 to 24*||8 to 32||8 to 32|
|- 8-port director||16||16 to 48*||16 to 48*||16 to 64||16 to 64|
|- 12-port director||24||24 to 72*||24 to 72*||24 to 96||24 to 96|
|Number Concurrent I/Os|
|- ESCON 4-port||4||4 to 12||8 to 24||4 to 16||8 to 32|
|- FICON 2-port||4||N/A||4 to 12||N/A||4 to 16|
|- SCSI 4-port||4||8 to 24||8 to 24||8 to 32||8 to 32|
|- 2-port director||4||4 to 12||4 to 12||4 to 16||8 to 16|
|- 4-port director||8||4 to 12||8 to 24||8 to 32||8 to 32|
|- 8-port director||4||4 to 12||4 to 12||4 to 16||4 to 16|
|- 12-port director||8||N/A||8 to 24||N/A||8 to 32|
* The standard configuration for the 8430 and 8530 consists of four channel directors and four cache boards. The number of channel directors can be increased to six by taking two of the cache board slots. However, this will reduce the maximum cache size by 50 percent.
All three models support Fibre Channel, SCSI, and ESCON connectivity. EMC announced that FICON support for S/390 is scheduled for general availability in the first quarter of 2002. It is backward compatible with all Symmetrix 8000 systems. EMC also announced the number of logical paths per ESCON port has been increased to 512. Refer to Table 1 for detailed comparisons of the connectivity options.
Fibre Channel directors will be available in 2-port, 4-port, 8-port, and 12-port versions. The 2-port version has two internal fibre paths, and the 4-port version has four internal fibre paths. The 8-port version has an internal hub with two internal paths. The 12-port version contains an internal switch and has four internal paths.
The new CacheStorm technology addresses bottlenecks that existing in the previous design of the Symmetrix global cache. Each of the cache boards in the previous design was treated as a single region with just one port (or path) to the buses. With the CacheStorm technology, each cache board is now segmented into four regions, with each region having a path to the buses. Requests for the cache are intelligently arbitrated to optimize the usage of the global cache, and the number of concurrent cache operations has been increased from four to sixteen.
The cache boards (or directors) contain Application Specific Integrated Circuits (ASICs) that act as intelligent offload engines to perform repetitive system functions, including buffering service requests for the cache. The ASIC then performs the operation (e.g. read/write to cache). Other functions include arbitrating incoming requests for cache resources.
Symmetrix also now supports up to sixteen independent LRUs. These independent LRUs are used by its Cache Quality of Service (QoS) feature to allow the user to define segments of cache to be managed by a separate LRU list to one or more designated logical volumes. The QoS feature provides the user with a means of ensuring high performance for specific applications.
RAID-10 for z/OS
The RAID-10 option enables the Symmetrix to stripe data (RAID-0) across a mirrored set of devices (RAID1). This allows more parallel I/O operations.
Dynamic parallel access volumes and multiple allegiance
EMC previously supported PAV/MA in mainframe environments, but did not support the dynamic capability. With this announcement, Symmetrix now supports dynamic PAV/MA.
EMC announced several enhancements to its Symmetrix Remote Data Facility (SRDF) product. Included is the ability to keep the links up while applying updates to the microcode. EMC also announced that GDPS support (converting PPRC commands to SRDF) is scheduled for generally availability in the first quarter of 2002.
TimeFinder supports up to two concurrent BCV operations, but previously the two BCVs could not be treated independently for split operations. EMC announced that one of the BCVs can now be split independent of one another.
EMC also announced that the eSNAP capability (Instant Full Volume Copy) is now supported for open system platforms.
Evaluator Group comments:
This new Symmetrix 8000 family represents one more "turn of the crank" on the Symmetrix 5.x architecture. It is not the much-anticipated Symmetrix 6, which Evaluator Group now expects to be announced in the latter half of 2002. Although rather broad in its scope, the motivation behind this announcement by EMC is to enhance its competitive position in the open systems consolidation market, and to narrow the gap between the performance of Symmetrix and the industry leading Hitachi Data Systems Lightning 9900 family.
The new 12-port Fibre Channel director, with its internal switch, provides connectivity enhancements for consolidation in non-SAN environments. FICON support will enhance consolidation efforts in mainframe environments.
Another major improvement provided by the new 8000 family is in the area of performance. This results from the increase in number and speed of the microprocessors, the increased number of concurrent ESCON I/O operations, and improvements in the cache operations with the CacheStorm Technology. Without apple-to-apple comparative benchmarks, it is not clear how the Symmetrix compares to the Hitachi Data Systems Lightning 9900 family.
The new 8230 model is interesting. Several years ago EMC also offered three models of Symmetrix, but it dropped the smallest version. It appears that EMC has resurrected this level of Symmetrix to address those midrange customers who need more feature/function than the CLARiiON product can provide.
With the increased capacity that the 8530 has when compared with the 8430, EMC stated that it believes that the 8530 will address the "sweet spot" of its market. Like the 8430, the 8530 can contain six channel directors to increase connectivity and throughput, but doing so limits the maximum cache capacity to 32GB. Therefore, Evaluator Group believes that connectivity and throughput issues may continue to be a factor with this particular model, and limit its applicability to the upper end of the enterprise market.================================================
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This was first published in October 2001