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EMC Symmetrix – DMX Models by Cabinets Types

December 6th, 2008 1 comment

The below is the true breakdown of the type of the EMC Symmetrix and EMC DMX machines to the type of cabinet properties it has. 

Starting with the Symm 3.0’s EMC introduced a 1/2 Hieght cabinets, Single Full Cabinet and a 3 Cabinet machine. The same ideas went into the Symm 4.0 and 4.8. 

Starting the Symm 5.0 and into Symm 5.5, EMC introduced the Badger cabinets, which where much slimmer and about 5 ft in height, it was a disaster with those cabinets. Really no one bought it. 

Starting the DMX800’s and DMX1000’s which are the single cabinet, EMC introduced the DMX2000’s in 2 cabinets and DMX3000 in 3 cabinet style. 

Also if you ever wondered where those Symm modell numbers came from

1st Digit: 3 = Open Systems. 5 = Mainframe. 8 = Mixed.
2nd Digit: Related to Cabinet size, dependant on Generation’
3rd Digit: 00 = 5¼” Drives. 30 = 3½” Drives              

The DMX uses 31/2″ Fiber Drives


Symmetrix Hardware Components

November 29th, 2008 No comments

There are various Components in a EMC Symmetrix series of machines.

To name a few

Disk Directors
Channel Directors (CA, FA, EA, FI, GI, FA2)
Memory Cards
Disk Drives
Power Supply
For 3 Bay cabinets (AC-DC PS and DC-DC PS)
Fan
Back End Disk Adapters
Back End Channel Adapters (CA, FA, EA, FI, GI, FA2)
Communication Card
EPO Module
Battery
Service Processor

RAID Technology

November 27th, 2008 No comments

Various Implementations of RAID Types with EMC Symmetrix / DMX and Clariion Technology.

RAID (Redundant Array of Inexpensive or Independent Disk)

RAID 0 – Striped Disk Array without Fault Tolerance: Provides data striping (spreading out blocks of each file across multiple disk drives) but no redundancy. This improves performance but does not deliver fault tolerance. If one drive fails then all data in the array is lost.

RAID 1 – Mirroring and Duplexing: Provides disk mirroring. Level 1 provides twice the read transaction rate of single disks and the same write transaction rate as single disks.

RAID 5 – Block Interleaved Distributed Parity: Provides data striping at the byte level and also stripe error correction information. This results in excellent performance and good fault tolerance. Level 5 is one of the most popular implementations of RAID.

Now Available 3 RAID 5 and 7 RAID 5 with EMC DMX Platform.

RAID 6 – Independent Data Disks with Double Parity: Provides block level striping with parity data distributed across all disks.

RAID 0 + 1A Mirror of Stripes: Not one of the original RAID levels, two RAID 0 stripes are created, and a RAID 1 mirror is created over them. Used for both replicating and sharing data among disks.

RAID S (3 + 1): EMC Symmetrix / DMX disk arrays use an alternate, proprietary method for parity RAID that they call RAID-S. Three Data Drives (X) along with One Parity device. RAID-S is proprietary to EMC but seems to be similar to RAID-5 with some performance enhancements as well as the enhancements that come from having a high-speed disk cache on the disk array.

RAID S (7+1): EMC DMX disk arrays use an alternate, proprietary method for parity RAID that they call RAID-S. Seven Data Drives (X) along with One Parity device. RAID-S is proprietary to EMC but seems to be similar to RAID-5 with some performance enhancements as well as the enhancements that come from having a high-speed disk cache on the disk array.