In this post we will cover some important aspects / properties / characteristics / differences between the EMC Symmetrix DMX-4 and EMC Symmetrix V-Max. It seems like a lot of users are searching on blog posts about this information.
From a high level, I have tried to cover the differences in terms of performance and architecture related to the directors, engines, cache, drives, etc
It might be a good idea to also run both the DMX-4 and V-max systems through IOmeter to collect some basic comparisons between the front end and coordinated backend / cache performance data.
Anyways enjoy this post, and possibly look for some more related data in the future post.
EMC Symmetrix DMX-4 EMC Symmetrix V-Max
Called EMC Symmetrix DMX-4 | Called EMC Symmetrix V-Max | |
DMX: Direct Matrix Architecture | V-Max: Virtual Matrix Architecture | |
Max Capacity: 1 PB Raw Storage | Max Capacity: 2 PB of Usable Storage | |
Max Drives: 1900. On RPQ: 2400 max | Max Drives: 2400 | |
EFD’s Supported | EFD’s Supported | |
Symmetrix Management Console 6.0 | Symmetrix Management Console 7.0 | |
Solutions Enabler 6.0 | Solutions Enabler 7.0 | |
EFD: 73GB, 146GB, 200GB, 400GB | EFD: 200GB, 400GB | |
FC Drives: 73GB, 146GB, 300GB, 400GB, 450GB | FC Drives: 73GB, 146GB, 300GB, 400GB | |
SATA II: 500GB, 1000 GB | SATA II: 1000 GB | |
FC Drive Speed: 10K or 15K | FC Drive Speed: 15K | |
SATA II Drive Speed: 7.2K | SATA II Drive Speed: 7.2K | |
Predecessor of DMX-4 is DMX-3 | Predecessor of V-Max is DMX-4 | |
DMX-4 management has got a bit easy compared to the previous generation Symmetrix | Ease of Use with Management — atleast with SMC 7.0 or so called ECC lite | |
4 Ports per Director | 8 Ports per Director | |
No Engine based concept | Engine based concept | |
24 slots | The concept of slots is gone | |
1 System bay, 9 Storage bays | 1 System bay, 10 Storage bays | |
No engines | 8 Engines in one System (serial number) | |
64 Fiber Channel total ports on all directors for host connectivity | 128 Fiber Channel total ports on directors/engines for host connectivity | |
32 FICON ports for host connectivity | 64 FICON ports for host connectivity | |
32 GbE iSCSI ports | 64 GbE iSCSCI ports | |
Total Cache: 512GB with 256 GB usable (mirrored) | Total Cache: 1024 GB with 512 GB usable (mirrored) | |
Drive interface speed either 2GB or 4GB, drives auto negotiate speed | Drive interface speed 4GB | |
Green color drive LED means 2GB loop speed, Blue color drive LED means 4GB loop speed | Only 4GB drive speed supported. | |
512 byte style drive (format) | 520-byte style drive (8 bytes used for storing data check info). Remember the clarion drive styles, well the data stored in both the cases is different. The 8 bytes used with the Symmetrix V-Max are the data integrity field based on the algorithm D10-TIF standard proposal | |
FAST: Fully Automated Storage Tiering may not be supported on DMX-4’s (most likely since the support might come based on a microcode level rather than a hardware level) | FAST: Fully Automated Storage Tiering will be supported later this year on the V-Max systems | |
Microcode: 5772 / 5773 runs DMX-4’s | Microcode: 5874 runs V-Max | |
Released in July 2007 | Released in April 2009 | |
Concepts of Directors and Cache on separate physical slots / cards | Concept of condensed Director and Cache on board | |
DMX-4 Timefinder performance has been better compared to previous generation | 300% better TImefinder Performance compared to DMX-4 | |
No IP Management interface into the Service Processor | IP Management interface to the Service Processor, can be managed through the customer’s Network — IP infrastructure | |
Symmetrix Management Console is not charged for until (free) DMX-4 | Symmetrix Management Console to be licensed at a cost starting the V-Max systems | |
Architecture of DMX-4 has been similar to the architecture of its predecessor DMX-3 | Architecture of V-Max is completely redesigned with this generation and is completely different from the predecessor DMX-4 | |
Microcode 5772 and 5773 has be build on previous generation of microcode 5771 and 5772 respectively | Microcode 5874 has been build on base 5773 from previous generation DMX-4 | |
No RVA: Raid Virtual Architecture | Implementation of RVA: Raid Virtual Architecture | |
Largest supported volume is 64GB per LUN | Large Volume Support: 240GB per LUN (Open Systems) and 223GB per LUN (Mainframe Systems) | |
128 hypers per Drive (luns per drive) | 512 hypers per Drive (luns per drive) | |
Configuration change not as robust as V-Max Systems | V-Max systems introduced the concept of concurrent configuration change allowing customers to perform change management on the V-Max systems combined to work through single set of scripts rather than a step based process. | |
DMX-4 does present some challenges with mirror positions | Reduced mirror positions giving customers good flexibility for migration and other opportunities | |
No Virtual Provisioning with RAID 5 and RAID 6 devices | Virtual Provisioning allowed now with RAID 5 and RAID 6 devices | |
No Autoprovisioning groups | Concept of Autoprovisioning groups introduced with V-Max Systems | |
Minimum size DMX-4: A single storage cabinet system, supporting 240 drives can be purchased with a system cabinet | Minimum size V-Max SE (single engine) system can be purchased with 1 engine and 360 drive max. | |
No concepts of Engine, architecture based on slots | Each Engine consists of 4 Quad Core Intel Chips with either 32GB, 64GB or 128GB cache on each engine with 16 front-end ports with each engine. Backend ports per engine is 4 ports connecting System bay to storage bay | |
Power PC chips used on directors | Intel Quad Core chips used on Engines | |
Powerpath VE support for Vsphere — Virtual machines for DMX-4 | Powerpath VE supported for Vsphere — Virtual machines for V-Max | |
Concept of Backplane exists with this generation of storage | V-Max fits in the category of Modular Storage and eliminates the bottle neck of a backplane | |
DMX-4 was truly sold as a generation upgrade to DMX-3 | V-Max systems have been sold with a big marketing buzz around hundreds of engines, millions of IOPs, TB’s of cache, Virtual Storage | |
Systems cannot be federated | The concept of Federation has been introduced with V-Max systems, but systems are not federated in production or customer environments yet | |
Directors are connected to the system through a legacy backplane (DMX — Direct Matrix Architecture). | Engines are connected through copper RAPID IO interconnect at 2.5GB speed | |
No support for FCOE or 10GB Ethernet | No support for FCOE or 10GB Ethernet | |
No support for 8GB loop interface speeds | No support for 8GB loop interface speeds | |
Strong Marketing with DMX-4 and good success | Virtual Marketing for Virtual Matrix (V-Max) since the product was introduced with FAST as a sales strategy with FAST not available for at least until the later part of the year. | |
No support for InfiniBand expected with DMX-4 | Would InfiniBand be supported in the future to connect engines at a short or long distance (several meters) | |
No Federation | With Federation expected in the upcoming versions of V-Max, how would the cache latency play a role if you had federation between systems that are 10 to 10 meters away? | |
Global Cache on Global Memory Directors | Global Cache on local engines chips: again as cache is shared between multiple engines, cache latency is expected as multiple engines request this IO | |
DMX-4 is a monster storage system | The V-Max building blocks (engines) can create a much larger storage monster | |
256GB total vault on DMX-4 systems | 200GB of vault space per Engine, with 8 engines, we are looking at 1.6TB of vault storage | |
Performance on DMX-4 has been great compared to its previous generation DMX, DMX2, DMX-3 | IOPS per PORT of V-Max Systems
128 MB/s Hits 385 Read 385 Write 128MB/s Hits 635 Read 640 Write |
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V-Max performs better compared to DMX-4 FICON | 2.2 x Performance on FICON compared to DMX-4 Systems.
2 Ports can have as many as 17000 IOPS on FICON |
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Large Metadata overhead with the amount of volumes, devices, cache slots, etc, etc | A reduction of 50 to 75% overhead with the V-Max related to metadata | |
SRDF Technology Supported | New SRDF/EDP (extended distant protection)
Diskless R21 passthrough device, no disk required for this passthrough |
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Symmetrix Management Console 6.0 supported, no templates and wizards | Templates and Wizards within the new SMC 7.0 console | |
Total SRDF Groups supported 128 | Total SRDF Groups supported 250 | |
16 Groups on Single Port for SRDF | 64 Groups on Single Port for SRDF | |
V-Max comparison on Connectivity | 2X Connectivity compared to the DMX-4 | |
V-Max comparison on Usability (Storage) | 3X usability compared to the DMX-4 | |
DMX-4 was the first version of Symmetrix where RAID6 support was rolled out | RAID 6 is 3.6 times better than the DMX-4 | |
RAID6 support on DMX-4 is and was a little premature | RAID 6 on V-Max (performance) is equivalent to RAID 1 on DMX-4 | |
SATA II performance on DMX-4 is better than V-Max | SATA II drives do not support the 520-byte style. EMC takes those 8 bytes (520 — 512) of calculation for data integrity T10-DIF standard proposal and writes it in blocks or chunks of 64K through out the entire drive causing performance degradation. | |
SATA II performance on DMX-4 is better than V-Max | The performance of SATA II drives on V-Max is bad the DMX-4 systems | |
Fiber Channel performance better compared to DMX and DMX-2’s. | Fiber Channel performance compared to DMX-4 improved by about 36% | |
DMX-4 start supporting 4GB interface host connectivity | Fiber Channel performance 5000 IOPS per channel | |
RVA not available on DMX-4 platforms | RVA: Raid Virtual Architecture allows to have one mirror position for RAID volumes allowing customers to used the rest of the 3 positions for either BCV’s, SRDF, Migration, etc, etc. | |
No MIBE and SIB with DMX-4. Rather the DMX-4 directors are connected through a common backplane. | MIBE: Matrix Interface Board Enclosure connects the Odd and the Evens or (Fabric A and Fabric B) Directors together. The SIB (System Interface Board) connects these engines together using Rapid IO | |
Director count goes from Director 1 on the left to Director 18 (Hex) on the right | Director count goes from 1 on the bottom to 16 (F) on the top, based on each engine having 2 directors. 8 Engines, 16 Directors. | |
2 Directors failures if not in the same fabric or bus, rather are not DI’s (Dual Initiators) of each other will not cause a system outage or data loss / data unavailable | Single engine failure (2 Directors) will not cause Data Loss / Data Unavailable and the system will not cause an outage. Failed components can be Directors, Engines, MIBE, PS’s, Fan, Cache in a single Engine or 2 directors. | |
Single loop outages will not cause DU | Single loop outages will not cause DU | |
More architectural details related to drives, cache, directors, cabinets, Mibe, SIB, Service Processor to come in the V-Max architecture expansion and modularity post over the next week.
Enjoy!!!!
“Single engine failure (2 Directors) will not cause Data Loss / Data Unavailable and the system will not cause an outage. Failed components can be Directors, Engines, MIBE, PS’s, Fan, Cache in a single Engine or 2 directors.”
that's not true cause each Engine does have connected own DEAs. Loosing and Engine means the data on this DAEs is not available from other engines.