Bad fibre channel performance: need howto

Bad fibre channel performance: need howto

[Mario Giammarco]

Hello,
I asked a similar question last week.
I discovered that my hard disk which can do 60mb/sec sequential read,
under linux/lsilogic40909 fibre hba gives only 30mb/sec, 45 if I tweak a
lot readahead (why  I need to?).

I have searched a lot in internet and it seems that:

1) fibrechannel howto was in sistina home page but now disappeared
2) fibrechannel specific mailing list for linux disappeared (archives
to)

Where can I search for help? 
Here it not seems appropriate to me. 

I have to find my bottleneck, please help with sending me docs.

-- 
Mario Giammarco

Re: Bad fibre channel performance: need howto

[Erling Nygaard]

Mario

I am/was the author of the FibreChannel HowTo. 

That howto slowly got outdated (Interesting how that happens when one does 
not have the same amount of spare time anymore...) and we eventually decided 
to take it off the Sistina website.

Not sure if the howto would have helped you in diagnosing this problem 
anyway ;)

Erling




On Fri, Nov 21, 2003 at 08:37:38PM +0100, Mario Giammarco wrote:
> Hello,
> I asked a similar question last week.
> I discovered that my hard disk which can do 60mb/sec sequential read,
> under linux/lsilogic40909 fibre hba gives only 30mb/sec, 45 if I tweak a
> lot readahead (why  I need to?).
> 
> I have searched a lot in internet and it seems that:
> 
> 1) fibrechannel howto was in sistina home page but now disappeared
> 2) fibrechannel specific mailing list for linux disappeared (archives
> to)
> 
> Where can I search for help? 
> Here it not seems appropriate to me. 
> 
> I have to find my bottleneck, please help with sending me docs.
> 
> -- 
> Mario Giammarco
> 
> -
> To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
> the body of a message to majordomo@vger.kernel.org
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-- 
Erling Nygaard (nygaard@sistina.com)

Key fingerprint:
CA00 CF4E 9438 E348 E503  7ECF 9D94 D993 982A BDE0

Re: Bad fibre channel performance: need howto

[Fabien Salvi]

Mario Giammarco a écrit:
> Hello,
> I asked a similar question last week.
> I discovered that my hard disk which can do 60mb/sec sequential read,
> under linux/lsilogic40909 fibre hba gives only 30mb/sec, 45 if I tweak a
> lot readahead (why  I need to?).
> 
> I have searched a lot in internet and it seems that:
> 
> 1) fibrechannel howto was in sistina home page but now disappeared
> 2) fibrechannel specific mailing list for linux disappeared (archives
> to)
> 
> Where can I search for help? 
> Here it not seems appropriate to me. 
> 
> I have to find my bottleneck, please help with sending me docs.
> 

Hello Mario,

If you want, I can send you an archive of the howto.
I've downloaded it a long time ago, before sistina removed it from their 
server.

But, it's true, it's a bit old. Therefore, there are some basic 
informations about protocol that could have some interest.

About your problem, I am not sure it's really because of FibreChannel.
There are a lot of differences between theorical values and real ones.
Which tool are you using for the benchmark ?


-- 
Fabien SALVI

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Re: Bad fibre channel performance: need howto

[Mario Giammarco]

Il lun, 2003-11-24 alle 11:55, Fabien Salvi ha scritto:

> Hello Mario,
> 


> If you want, I can send you an archive of the howto.
> I've downloaded it a long time ago, before sistina removed it from their 
> server.
> 
> But, it's true, it's a bit old

Yes send it to me please. I like to read all.

> About your problem, I am not sure it's really because of FibreChannel.
> There are a lot of differences between theorical values and real ones.
> Which tool are you using for the benchmark ?

I know but usually the "sequential read" is the easiest test to discover
if there are problems.

I have used hdparm and sg3 tools to do a quick sequential read test.
On ide world if hdparm tells me that I have  sequential transfer rate
lower than shown on web reviews it means that I have to tweak dma, etc.
and usually after tweaking I get performance promised.

Here there is little to tweak and I then discovered with a serious test
(tiobench) that write performance is also worse.

I suppose there is some problem.

I am now buying a qlogic2200 to try if it is better.
Can someone tell me best drivers for qlogic2200?


Thanks again!


-- 
Mario Giammarco

Re: Bad fibre channel performance: need howto

[Fabien Salvi]

Mario Giammarco a écrit:
> Il lun, 2003-11-24 alle 11:55, Fabien Salvi ha scritto:
> 
> 
>>Hello Mario,
>>
> 
> 
> 
>>If you want, I can send you an archive of the howto.
>>I've downloaded it a long time ago, before sistina removed it from their 
>>server.
>>
>>But, it's true, it's a bit old
> 
> 
> Yes send it to me please. I like to read all.

Here :
ftp://ftp.cri74.org/incoming/services/3c6caf61efc733e03526edac45852ad1/fibrechannel_howto.tar.bz2

>>About your problem, I am not sure it's really because of FibreChannel.
>>There are a lot of differences between theorical values and real ones.
>>Which tool are you using for the benchmark ?
> 
> 
> I know but usually the "sequential read" is the easiest test to discover
> if there are problems.
> 
> I have used hdparm and sg3 tools to do a quick sequential read test.
> On ide world if hdparm tells me that I have  sequential transfer rate
> lower than shown on web reviews it means that I have to tweak dma, etc.
> and usually after tweaking I get performance promised.
> 
> Here there is little to tweak and I then discovered with a serious test
> (tiobench) that write performance is also worse.
> 
> I suppose there is some problem.
> 
> I am now buying a qlogic2200 to try if it is better.
> Can someone tell me best drivers for qlogic2200?

I use qlogic 2200 FC HBA with the official qlogic driver and it works 
fine. Look at: 
http://www.qlogic.com/support/os_detail.asp?productid=113&osid=26

-- 
Fabien SALVI      Centre de Ressources Informatiques
                   Archamps, France -- http://www.cri74.org
                   PingOO GNU/linux distribution : http://www.pingoo.org

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