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October 29th, 2018 23:00

Storage Usable Capacity

Hi,

 

How to calculate usable capacity for 1.92TB x 7 SSD (single redundancy - tier 1) and 6TB x 11 HDD (dual redundancy - tier 2/3)

 

Thank you

Moderator

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7.6K Posts

October 30th, 2018 09:00

Hello SC Newbie,

Here is a link to a guide for Understanding RAID with Dell SC Series Storage.  http://en.community.dell.com/techcenter/extras/m/white_papers/20442059

Please let us know if you have any other questions.

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6 Posts

October 30th, 2018 16:00

Hi Sam,

Thank you for the response.

I have read the document but still have no answer. Can you explain me how to calculate usable capacity ? Because single redundancy contains 2 kinds of raid (10 and 5) and dual redundancy contains 2 kinds of raid (10DM and 6).

 

Thank you

Moderator

 • 

7.6K Posts

October 31st, 2018 08:00

Hello SC Newbie,

Here is a breakdown of how the Raid is used.

 

Type

Raid Type

Description

Required Disks

Data Disks

Overhead %

Efficiency %

Redundant

R10-2

Mirror

2

1

100%

50%

Redundant

R5-5

Parity

5

4

25%

80%

Redundant

R5-9

Parity

9

8

12.50%

88.75%

 

 

 

 

 

 

 

Dual Redundant

R10-DM

Dual Mirror

3

1

200%

33.33%

Dual Redundant

R6-6

Dual Parity

6

4

50%

66.66%

Dual Redundant

R6-10

Dual Parity

10

8

25%

80%

Please let us know if you have any other questions.

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