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VNX virtual provisioning and storage tiering

If I have Unisphere Suite and Basic VNX Software (it is a VNX5400 array), does  it make sense to configure pools consisting of performance and capacity drives, if I only have the Virtual Provisioning enabler installed? Will I be able to take advantage of storage tiering without FAST VP enabler?


Any input is appreciated.

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6 Replies
brettesinclair
3 Silver

Re: VNX virtual provisioning and storage tiering

I've always used Fast VP, so I'm not 100% sure, but I think you'll only be able to create homogeneous pools.(single drive type per pool)

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Roger_Wu
4 Ruthenium

Re: VNX virtual provisioning and storage tiering

Without FAST VP, you could not enable the auto-tiering feature which can automatically move the "hot data" to performance (SSD) tier..

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Re: VNX virtual provisioning and storage tiering

I do not have SSDs, only SAS and NLSAS. Trying to figure out if it will make sense to put them in the same pool if I do not have FAST VP, only VNX Base software and Unisphere suite, which includes virtual provisioning. Not sure if in this case VP will do tiering between SAS and NLSAS. If not, whats the benefit of putting them in the same pool?

Regards

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Rainer_EMC
5 Rhenium

Re: VNX virtual provisioning and storage tiering

IF you are planning to use thin LUNs or deduplication it does make sense to have some SSD’s in the pool even without FAST because the meta data needed for both will then be allocated on SSD for faster access

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Re: VNX virtual provisioning and storage tiering

Thanks Rainer, yes, I am planning to use thin LUNs, but I will have no storage-tiering without FAST VP anyway, will I? Adding SSDs is not an option. I am trying to figure out what will be the benefits to configure pools consisting of SAS and NLSAS drives, or it is going to make more sense to go with traditional RGs.

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rzero
1 Nickel

Re: VNX virtual provisioning and storage tiering

I'm still a little confused on what exactly you are asking so I'm going to give a couple responses:

  1. "I have multiple disk types but no FAST VP license, should I still create a pool with multiple tiers? I have no FAST enablers on but it is still letting me create a pool with multiple tiers!" - I didn't think it would let you create a multiple tiered pool without the FAST suite but I'll take your word for it.  I know for certain you cannot schedule tiering without the enabler. In this case I would not create a tiered pool unless you had plans to purchase FAST licensing quickly because this is likely just going to place data in the order you create it, filling up the SAS tier and then moving to the NLSAS tier, and then never moving it again.  You would have a tiered pool, but fixed data locality...a bad combination.  Much better to have 2 separate pools, and then you control what kind of data goes in them.  You can even LUN migrate back and forth if necessary.
  2. "No, I meant that I have multiple disk types but no FAST VP licensing, and I'm wondering should I use storage pools (single tier pools with only one disk type) or RAID groups?" - I don't think this is the question you are asking but just in case.  Outside of an odd corner case, I would use pools for the following reasons:
    • Pools have more flexibility and less management overhead in general
    • In order to leverage multiple sets of spindles, you have to manage MetaLUNs on RGs.  With pools you don't have to deal with that animal as everything hits the entire disk set.
    • Similar to the previous point, dealing with performance or capacity issues that require you throw additional resources into your array are much simpler with pools than with RGs.
    • By purchasing additional licensing (like FAST) you can do new things with an existing pool.  For instance you could enable FAST VP, LUN migrate to one pool or the other, and then destroy the empty pool before adding it as a tier to the new pool.  With RAID groups it will be very painful to move forward without purchasing a lot of new disk.

Did one or both of those responses help?

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