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pizzim13
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VddkPreReadBufferSize reg entry (from VMWorld)

Post by pizzim13 » Oct 01, 2012 6:21 pm

Would Veeam, setup to use hotadd and virtual proxies, possibly benefit from this registry entry? If so, does this change need to be made on my Veeam "job scheduler" or just the virtual proxies? I remember from the session that my mileage may vary due to my storage.

Gostev
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Re: VddkPreReadBufferSize reg entry (from VMWorld)

Post by Gostev » Oct 01, 2012 10:32 pm

The result only depends on actual storage, and nothing else. The default value is optimal for vast majority of storage devices, in rare cases increasing this value can significantly improve the full backup performance - but in many cases, doing this will also impact the incremental backup performance.

The key needs to be set on backup management server, and its value will be used by all backup proxies automatically.

pizzim13
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Re: VddkPreReadBufferSize reg entry (from VMWorld)

Post by pizzim13 » Oct 02, 2012 2:47 am

I know in the session you said that the default was 4MB. What should the default value be for reg key?

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Re: VddkPreReadBufferSize reg entry (from VMWorld)

Post by Gostev » Oct 02, 2012 10:48 am

The key should simply not exist for the default value to be used.

pizzim13
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Re: VddkPreReadBufferSize reg entry (from VMWorld)

Post by pizzim13 » Oct 02, 2012 11:17 am

Correct. What I meant to ask is, for example, how would the value of 4MB be represented in the reg key? 4, 4096, etc

Vitaliy S.
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Re: VddkPreReadBufferSize reg entry (from VMWorld)

Post by Vitaliy S. » Oct 02, 2012 2:01 pm

This is a DWORD value in bytes.

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Re: VddkPreReadBufferSize reg entry (from VMWorld)

Post by Gostev » Oct 02, 2012 7:28 pm

4194304 (4 x 1024 x 1024), but make sure you are entering value as DEC
Default setting for registry editor is HEX, and base 16 value is 400000

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