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DukeR1337

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DukeR1337

2 Intern

208 Posts

1

1463

March 20th, 2018 08:00

How much SSD Tier for a hybrid one?

Hi all

Is there a general advice or white paper about how much SSD capacity (tier) we should install in a pool for tiering? 20%?

Cheers and thanks

  • kelleg

    6 Operator

    4537 Posts

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    Posted March 20th, 2018 15:00

    See the Unity Best Practices White Paper

    h15093-Dell_EMC_Unity-Best_Practices_Guide.pdf

    glen

  • DukeR1337

    2 Intern

    208 Posts

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    0

    Posted March 21st, 2018 02:00

    Well the statement looks like "put us much as possible" which is not really a quiantifier any recommendation based on your experience?

  • Rainer_EMC

    6 Operator

    8645 Posts

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    Posted March 21st, 2018 08:00

    I would see that as a minimum - esp. for thin provisioning since this also includes the metadata which is preferably put on flash

    So if you want 5% user data on flash you need more than that

  • kelleg

    6 Operator

    4537 Posts

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    Posted March 21st, 2018 08:00

    Page 13:

    Dell EMC recommends provisioning a Flash tier in hybrid pools. The Flash tier helps enable pool performance efficiencies, and improves response times when using Snapshots and/or Replication. The minimum recommended Flash capacity is at least 5% of the pool capacity.


    The minimum should be at least one, 4+1 R5 - more is the size of the Pool is very large, then use the 5% recommendation.

    Also, pay particular attention to the section on page 11 "GENERAL RECOMMENDATIONS".

    glen

  • DukeR1337

    2 Intern

    208 Posts

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    0

    Posted March 22nd, 2018 01:00

    Hi both,

    Thanks very much I think I can work with this! I appreciate your patience and engagement.

    Cheers

  • kelleg

    6 Operator

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    Posted March 27th, 2018 07:00

    Was your question answered correctly? If so, please remember to mark your question Answered when you get the correct answer and award points to the person providing the answer.

    Remembering to mark the question Answered helps others with similar problems and awarding points helps motivate people to take the time answer you questions. Forgetting this may affect responsiveness.

    glen