Lots of testing of various stores under various situations. As you know SIS has been eliminated from Exchange 2010 and a form of store compression introduced. This, along with the other capabilities of the NetApp platform have played right into our hands. NetApp is the only vendor to offer deduplication on primary data. The deduplication is not an in-line process but rather is scheduled. Hourly, twice daily, daily, weekly, whatever. You set it to suit your requirements.
Oversimplification alert: The process runs through a particular volume and checks all the blocks to ascertain whether or not the checksums are identical. Once done a walk is done through the bits to make sure that the blocks with identical checksums are indeed identical (a certain vendor has suffered lost customer data by failing to do that part)
What does this mean for Exchange?
Nothing. Exchange doesn't understand storage, doesn't see a difference and doesn't experience any kind of a performance drop. In fact, leveraged with PAM, the performance of Exchange actually goes UP!!
What does this mean for your storage?
Stores which experience a lot of attachments get around 23% back. Stores which have an awful lot of message body content but very little in the way of attachments experience a return of around 10%. YOUR MILEAGE WILL VARY!!!!!
What does this mean for you?
$$$
If you've got ten stores of about 1TB each the broad-brush returns are that you only consume space for about nine of them. As your stores get large the amount of space returned goes up, even if the ratio hovers around the same place. You buy enough storage for the ten stores and you get the log space for free. That's in addition to the amount of space you gain by spreading your stores across an aggregate of disks. An alternative way of looking at it is if you experience a daily change rate of 5% - not an unreasonable number - then you get a couple of days worth of snapshots for free since you don't need to factor that extra space into your capex. Given that only NetApp can cope with multiple online snapshots without performance degredation the amount of space regained by deduplication really does come in handy.
Ddeduplication on small Exchange 2010 stores that have a high turnover and policies that delete old mail within a smallish number of days probably isn't too productive but consider that against the online archive and the fact that people with huge mailboxes are never going to touch most of their mailbox and you're seeing a lot of 'wasted' storage, about which you can do nothing. Except on NetApp.
Shiny, huh? And one of the many reasons I enjoy working for the company. Cool Exchange-enhancing technologies.
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2 comments:
but a NetApp drive is twice the cost of a HP DAS/MSA drive and thats forgetting the cost of the filer head and dedup license.
Also would you put multiple copy of a DAG on the same filer head....NO! as this is a point of failure. So your only dedup messages in different database on the same DAG members,
Therefore the saving is minimal and outweighed by dumping the NetApp and going DAS and JBOD!
FAS 2040 systems will work out to have the same TCO as the MSA class solutions. You WILL use fewer disks. You WILL have a data protection solution. The MSA gives you none of that so in addition to using more disk to store data you need to use yet more disk to protect Exchange. If you don't protect Exchange you use copy 4 and maybe 5 and lag them. That's two extra servers and 200% additional storage.
If you have a NetApp solution you will not dump it.
If you are in a competitive market to implement Exchange you're going to look at DAS and what the storage vendors do and you're going to make an informed decision on what solution to implement.
And if you can get 20% deduplication on a single database you're already onto a winner. If you choose to put two stores in the same FlexVol you're going to get a greater space saving. You're going to lose some granularity of restore though so it's something you have to think about. Carefully.
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