Re: Filesystem Block Size ? 1K or 4K or 8K ?

From: Zhu,Chao <zhuchao_at_gmail.com>
Date: Tue, 14 Oct 2008 21:32:09 +0800
Message-ID: <962cf44b0810140632r69744beao2b47b50851abf2fd@mail.gmail.com>


Q1: I don't have performance test result about HP vxfs. But vxfs_at_solarisusing directio does not seems to make much difference per my past
experience. And whether direct IO helps/how much it helps really depends on application profile. Same with Raw Devices. (more heavy write, more saving on CPU and better throughput.)

Q2: see metalink note *139272.1

*I don't see any benefit of using 1k/4k filesystem pagesize for a 8k db_block_size database. Won't consider that at all.

On Tue, Oct 14, 2008 at 7:49 PM, VIVEK_SHARMA <VIVEK_SHARMA_at_infosys.com>wrote:

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> ------------------------------
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> *From:* zhuchao_at_gmail.com [mailto:zhuchao_at_gmail.com]
>
> If direct io is being used, the difference maybe less.
>
> *Qs 1 -> What do you mean by "the difference maybe less."?*
>
>
> Anyway I don't see any benefit using 1k/4k blocksize.
> If you want best throughput, go with raw volumes.
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> Have done all tuning on hp kaio setup to maximize os capability?
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> *Qs 2 -> Could you share some "tuning on hp kaio setup" please?*
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> HP who is partnering the Benchmark states - since Filesystems are being
> Mounted with *Direct I/O* therefore 1K F.S. block size is preferred to 8K.
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> ------------------------------
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> *From:* zhuchao_at_gmail.com [mailto:zhuchao_at_gmail.com]
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> Of course set to 8k
> ------------------------------
>
> We are in the process of Setting up DB Server for an OLTP Banking
> Application Benchchmark.
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>
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> HP-UX B.*11.31*
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> system device block size(think this is the O.S. block size) = 1K
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> Base page size = 4K.
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> DB_block_size = 8K
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> Should the Filesystem (VXFS) Block Size be set to *1K, 4K or 8K? *Personally I think it should be 4 K (i.e. Equal to the Page-size)
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-- 
Regards
Zhu Chao
www.cnoug.org

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Received on Tue Oct 14 2008 - 08:32:09 CDT

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