FreeBSD 7.1 disk performance issue on ESXi 3.5

ivoras at ivoras at
Fri Feb 13 12:01:23 PST 2009

On Feb 13, 2009 8:27pm, Josh Paetzel <josh at> wrote:

> In my limited experience with VMWare linux seems to have near bare metal  
disk performance. FreeBSD seems to incur a significant performance penalty.  
For instance on my laptop, running OSX and VMWare Fusion, FreeBSd virtual  
machines can't saturate 100TX off the disk, raw dd manages about 7  
Megs/sec, which is in line with what I get shovelling big files around.  
Disk is a 7200 RPM SATA2.

You might want to try the patch Scott Long made recently  
( - I found it doubles the  
performance in some cases for VMWare (writing mostly, though sequential  
reading can be similarly improved by the combination of this patch and  
increasing vfs.read_max), but it's still worse than with Linux (100 MB/s vs  
150 MB/s).

As for the original thread topic: I've communicated with the OP and it  
appears his method of benchmarking had an error so the problems that appear  
in his post are bogus.

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