Disk performance on ESXi with FreeBSD 7.1

[Charles Owens]

Charles Owens wrote:
> Scott Long wrote:
>   
>> Sebastiaan van Erk wrote:
>>     
>>> Hi,
>>>
>>> I'm running FreeBSD on ESXi but I'm having serious issues with disk
>>> performance, and I'm wondering if it might have something to do with
>>> the scsi driver (or the virtual hardware not returning proper values
>>> for its capabilities or something)..
>>>
>>> ...
>>>       
>> Run the following command:
>>
>> sudo camcontrol tags da0
>>
>> If it returns something like this:
>>
>> (pass0:mpt0:0:0:0): device openings: 1
>>
>> then run the following command:
>>
>> sudo camcontrol tags da0 -N 64
>>
>> If this works in improving performance, it can be put into a startup
>> script.  I have no idea why the controller is misbehaving with this yet,
>> but I'm working on it.
>>
>> Scott
>>
>>     
> I'm also seeing poor performance (much less than linux), running within
> ESX Server... I'm using FreeBSD i386, single CPU, 1 GB RAM.
>
> I've run the "camcontrol tags da0 -N 64" command and have seen
> significant improvement (dbench numbers boosted by factor of 5 or so).  
> Not sure it's quite enough, compared to Linux... but a big help already
> (thanks!)

Hmmm... my comparison with Linux here was reckless, sorry about that...
please consider it withdrawn.  What I definitely was seeing was a
performance drop between FreeBSD 7.0 and 7.1 -- the CAM "tags"
regression that you announced this morning.

Thanks for sorting this out!

**Charles Owens**
*Great Bay Software*****