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[ iometer-Bugs-3397626 ] Block device - block size, Inaccurate Results

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[ iometer-Bugs-3397626 ] Block device - block size, Inaccurate Results

SourceForge.net
Bugs item #3397626, was opened at 2011-08-24 14:51
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https://sourceforge.net/tracker/?func=detail&atid=427254&aid=3397626&group_id=40179

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Category: None
Group: None
Status: Open
Resolution: None
Priority: 5
Private: No
Submitted By: https://www.google.com/accounts ()
Assigned to: Nobody/Anonymous (nobody)
Summary: Block device - block size, Inaccurate Results

Initial Comment:
Under linux, dynamo opens physical device without O_DIRECT flag, resulting in higher performance due to device buffered i/o.
Example:  Sector Size 512, Block Size 4096.
Access Specification:  512 Bytes Read.

Test will open the block device and perform 4096 reads opposed to 512, resulting in ~8x higher performance.

Fix:  In function TargetDisk::Open (ln 1499 on iometer-1.1.0-rc1-src), add O_DIRECT to open flags.

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You can respond by visiting:
https://sourceforge.net/tracker/?func=detail&atid=427254&aid=3397626&group_id=40179

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