[Samba] Dynamic Link Aggregation via Samba

Patrik patrikb at scientology.net
Mon Oct 12 00:34:49 MDT 2009


Hi Adam,

Do you have any idea why SMB on MAC would be half the speed than AFP? (
As mentioned below). I.e. do you have any recommendations on better
socket options or similar that could yield a higher speed over SMB?

Best, Patrik

>>>>> -----Original Message-----
>>>>> From: Patrik [mailto:patrikb at scientology.net]
>>>>> Sent: Wednesday, 7 October 2009 15:09
>>>>> To: Adam Nielsen
>>>>> Subject: Re: [Samba] Dynamic Link Aggregation via Samba
>>>>>
>>>>> Hi Adam,
>>>>>
>>>>> Thanks for your reply. In regards to speed I meant 600 Megabytes per
>>>>> second. I.e. I bonded 6 Gigabit ports together on my server.
>>>>>
>>>>> AFP stands for AppleTalk Filing Protocol. The protocol that non-Apple
>>>>> networks need to use in order to access data in an AppleTalk server.
>>>>>
>>>>> I have a gigabit NIC (network interface card) in my G5 on my desktop.
>>>>> Gigabit is about 123 Megabytes per second per what I gathered on the
>>>>> net. However when you have more users and traffic you can actually never
>>>>> reach that full spectrum more like 40 MB/s. By adding Network interface
>>>>> cards to my server and bonding them I was able to up the speed via
>>>>> Appletalk up to about 90-100 Megabytes per second stably - closer to
>>>>> home. However via SMB I was not able to get that speed increase.
>>>>>
>>>>> I literally copy the same file just using the other protocol and the
>>>>> speed goes down. Then when I copy the file via AFP I get the expected
>>>>> result.
>>>>>
>>>>> I was told it has to do with the socket options of SMB and how Samba
>>>>> passes packets over to the TCP IP layer etc. So I increased the sendbuff
>>>>> size on my CentOS server but this did not result in the increase I
>>>>> expected. Still about 53 Megabytes per second. So I am looking for any
>>>>> info on how to get max bandwidth over gigabit via Samba. I.e. other
>>>>> settings that I need to tweak? Or maybe settings that I have to change
>>>>> on my G5 in terminal? Any ideas?
>>>>>
>>>>> The server is capable of 250 Megabytes per second write speed that I am
>>>>> trying to connect to. (that is not that fast but still faster than the
>>>>> network speed.)
>>>>>
>>>>> Best, Patrik
>>>>>
>>>>> PS: Are the pgms you mentioned available for Power PCs (the older
>>>>> non-intel based macs? Also would they help me tweak Samba or more for
>>>>> speed checking?
>>>>>
>>>>> Adam Nielsen wrote:
>>>>>       
>>>>>           
>>>>>>> I have run into the following I bonded 6 NICs on my Cent OS server
>>>>>>>           
>>>>>>>               
>>>> into
>>>>     
>>>>         
>>>>>>> a 600MB pipe. I use bond method 4 = dynamic Link aggregation. My Cysco
>>>>>>> Switch supports this apparently.
>>>>>>>    
>>>>>>>           
>>>>>>>               
>>>>>> Do you mean your aggregated bandwidth is 600Mbps (megabits/sec) or
>>>>>> 600MBps (megabytes/sec)?  I'm assuming 6 x 10/100 == 600Mbps.
>>>>>>
>>>>>>  
>>>>>>         
>>>>>>             
>>>>>>> I did these changes and still top out at 53 MB/s however via AFP I am
>>>>>>> able to get an average of 90MB/s up to tops 103MB/s. It seems
>>>>>>>           
>>>>>>>               
>>>> really odd
>>>>     
>>>>         
>>>>>>> that I cannot tweak SMB to utilize the pipe properly. Any ideas on
>>>>>>>           
>>>>>>>               
>>>> what
>>>>     
>>>>         
>>>>>>> settings I need to tweak to make this work?
>>>>>>>    
>>>>>>>           
>>>>>>>               
>>>>>> I'm afraid I don't know what AFP is, but on a 600Mbps network link your
>>>>>> maximum throughput will be ~60MB/sec, so it seems that 53MB/sec isn't
>>>>>> that bad.  I'm not sure how you can get 100+MB/sec as that's gigabit
>>>>>>         
>>>>>>             
>>>> speed.
>>>>     
>>>>         
>>>>>> You could use a program like ttcp to verify how much data you can move
>>>>>> over your network link, and a program like Bonnie to see how much data
>>>>>> you can read off your disk.  If you have slow disks it won't matter how
>>>>>> much network bandwidth you have available.  (Unless you share a tmpfs
>>>>>> filesystem over Samba for testing.)
>>>>>>
>>>>>> Cheers,
>>>>>> Adam.
>>>>>>
>>>>>>
>>>>>>  
>>>>>>         
>>>>>>             
>>>>     
>>>>         
>>>   
>>>       
>
>   



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