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From:Johan De Meersman Date:July 29 2013 10:37pm
Subject:RE: hypothetical question about data storage
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Rick James <rjames@stripped> wrote:
>
>For MySQL + RAID, a Linux elevator strategy of 'deadline' or 'noop' is
>optimal.  (The default, 'cfq', is not as good.)

I should look into those again at some point. Do you have a brief word as to why they're
better?


>A RAID controller with multiple drives striped (and optionally
>parity-checked) (RAID-5, -10) and with a BBU (Battery Backed Write
>Cache) is excellent for I/O.

Very true. 10 is traditionally considered better - it's certainly faster - but 5 is of
course cheaper :-) 

I'd like to add that 4+1 is the optimal configuration for RAID5 , as that makes for a
stripe of 2kb, assuming 512b sectors of course. You then pick an fs that supports blocks
of that size , which means that no write will ever need to perform a read first to
calculate the checksum.




-- 
Sent from my Android phone with K-9 Mail. Please excuse my brevity.
Thread
hypothetical question about data storageChris Knipe25 Jul
  • Re: hypothetical question about data storageVahric Muhtaryan25 Jul
  • Re: hypothetical question about data storageJohan De Meersman26 Jul
    • Re: hypothetical question about data storageChris Knipe26 Jul
      • RE: hypothetical question about data storageRick James26 Jul
        • RE: hypothetical question about data storageJohan De Meersman26 Jul
          • Re: hypothetical question about data storageChris Knipe26 Jul
            • Re: hypothetical question about data storagehsv27 Jul
            • Re: hypothetical question about data storagewilliam drescher27 Jul
              • RE: hypothetical question about data storageRick James29 Jul
                • RE: hypothetical question about data storageJohan De Meersman29 Jul
                  • RE: hypothetical question about data storageRick James29 Jul
                    • Re: hypothetical question about data storageCarsten Pedersen30 Jul
                    • Re: hypothetical question about data storageManuel Arostegui30 Jul
                    • RE: hypothetical question about data storageJohan De Meersman30 Jul