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EMC Symmetrix: Calculations for Heads, Tracks, Cylinders, GB


Symmetrix Disk Drive

Here is the quick and dirty math on EMC Symmetrix Heads, Tracks, Cylinder sizes to actual usable GB’s of space.

Based on different generations of Symmetrix systems, here is how the conversions work.

Before we jump into each model type, lets look at what the basics are, with the following calculations.

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There are s number of splits (hyper) per physical device.

There are n number of cylinders per split (hyper)

There are 15 tracks per cylinder (heads)

There are either 64 or 128 blocks of 512 bytes per track

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All the calculations discussed here are for Open Systems (FBA) device types. Different device emulations like 3380K, 3390-1, 3390-2, 3390-3, 3390-4, 3390-27, 3390-54 have different bytes/track, different bytes/cylinder and cylinders/volume.

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Symmetrix 8000/DMX/DMX-2 Series

Enginuity Code: 5567, 5568, 5669, 5670, 5671

Includes EMC Symmetrix 8130, 8230, 8430, 8530, 8730, 8830, DMX1000, DMX2000, DMX3000 and various different configurations within those models.

GB = Cylinders * 15 * 64 * 512 / 1024 / 1024 / 1024

eg: 6140 Cylinder devices equates to 2.81 GB of usable data

6140 * 15 * 64 * 512 / 1024 / 1024 / 1024 = 2.81 GB

Cylinders = GB / 15 / 64 / 512 * 1024 * 1024 * 1024

Where

15 = tracks per cylinder

64 = blocks per track

512 = bytes per block

1024 = conversions of bytes to kb to mb to gb.

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Symmetrix DMX-3/DMX-4 Series

Enginuity Code: 5771, 5772, 5773

Includes EMC Symmetrix DMX-3, DMX-4 and various different configurations within those models.

GB = Cylinders * 15 * 128 * 512 / 1024 / 1024 / 1024

Eg: 65520 Cylinder device equates to 59.97 GB of usable data

65540 * 15 * 128 * 512 / 1024 / 1024 / 1024 = 59.97 GB

Cylinders = GB / 15 / 128 / 512 * 1024 * 1024 * 1024

15 = tracks per cylinder

128 = blocks per track

512 = bytes per block

1024 = conversions of bytes to kb to mb to gb

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Symmetrix V-Max

Enginuity Code: 5874

Includes EMC Symmetrix V-Max and various different configurations within this model.

GB = Cylinders * 15 * 128 * 512 / 1024 / 1024 / 1024

Eg: 262668 Cylinder device equates to 240.47 GB of usable data

262668 * 15 * 128 * 512 / 1024 / 1024 / 1024 = 240.47 GB

Cylinders = GB / 15 / 128 / 512 * 1024 * 1024 * 1024

15 = tracks per cylinder

128 = blocks per track

512 = bytes per block

8 bytes = 520-512 used for T10-DIF

1024 = conversions of bytes to kb to mb to gb

Drive format on a V-Max is 520 bytes, out of which 8 bytes are used for T10-DIF ( A post on DMX-4 and V-Max differences).