amgtar with blocksize set to 512 performs at the same speed.

If I mount the partition on the backup server via NFS then the backup runs 
about 6x quicker. So I'm assuming it must be something related to way AMANDA 
sets up up the TCP connection. Although obviously open to other suggestions.

Alan


----------------------------------------
> Date: Wed, 21 Oct 2009 06:59:01 -0400
> From: martineau AT zmanda DOT com
> To: ap_griffiths AT hotmail DOT com
> CC: dustin AT zmanda DOT com; amanda-users AT amanda DOT org
> Subject: Re: TCP Tuning
>
> Use the amgtar application and set the TAR-BLOCKSIZE to a bigger value
> (half the STREAM_BUFSIZE.
>
> Why do you believe it is bottleneck?
>
> Jean-Louis
>
> Alan Griffiths wrote:
>> Thanks for the pointer.
>>
>> I've re-compiled with
>>
>> define STREAM_BUFSIZE (NETWORK_BLOCK_BYTES * 16)
>>
>> And I can see that has taken effect on the server
>>
>> dumper: try_socksize: send buffer size is 524288
>>
>> But backups are running no faster and I cannot see any indication on
>> the client of the buffer size being used. Note: client also has the
>> new binaries. In older versions of AMANDA amandad used to report
>> buffer size, but this appears to not be the case in 2.6.1p1.
>>
>> Thanks,
>>
>> Alan
>>
>>> Date: Mon, 19 Oct 2009 10:03:21 -0400
>>> Subject: Re: TCP Tuning
>>> From: dustin AT zmanda DOT com
>>> To: ap_griffiths AT hotmail DOT com
>>> CC: amanda-users AT amanda DOT org
>>>
>>> On Mon, Oct 19, 2009 at 5:33 AM, Alan Griffiths
>>>  wrote:
>>>> Is there a way to modify the size of the TCP buffers used by
>> AMANDA? I am
>>>> trying to improve performance over a relatively high latency link
>> and this
>>>> seems to be the only way.
>>>
>>> It's a source constant, unfortunately, set in stream.h (STREAM_BUFSIZE).
>>>
>>> A patch to make that configurable at compile time or, better, at
>>> runtime would be much appreciated!
>>>
>>> Dustin
>>>
>>> --
>>> Open Source Storage Engineer
>>> http://www.zmanda.com
>>
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