thanks for information, Chris.
Brian, should we set it to htcp?
thanks
Elena
On 4 Aug 2011, at 12:47, Christopher J.Walker wrote:
> For those of you who didn't know how to check which congestion control
> you are using:
>
> [root@se04 ~]# cat /proc/sys/net/ipv4/tcp_congestion_control
> bic
>
>
> [log in to unmask] wrote:
>> Recommendation from the fasterdata people is to use htcp as it solves
>> a couple of kernel bugs in BIC and CUBIC for certain version s of the
>> kernel . ( Plus probably utilizes bandwidth more than BIC).
>>
>
>
> Indeed from the hoses mouth:
>
> http://fasterdata.es.net/fasterdata/host-tuning/linux/
>
> "For long fast paths, we highly recommend using cubic or htcp. Cubic is
> the default for a number of Linux distributions, but if is not the
> default on your system, you can do the following:
>
> sysctl -w net.ipv4.tcp_congestion_control=cubic
>
> NOTE: There seem to be bugs in both bic and cubic for a number of
> versions of the 2.6.18 kernel used by Redhat Enterprise Linux 5.3 - 5.5
> and its variants (Centos, Scientific Linux, etc.) We recommend using
> htcp with a 2.6.18.x kernel to be safe."
>
>
> QMUL has been using bic, but I'll change things to use htcp on our
> gridftp node.
>
> AFAICT, the approved way of making this permanent is:
>
> [root@se04 ~]# echo modprobe tcp_htcp >>/etc/rc.modules
> [root@se04 ~]# chmod +x /etc/rc.modules
>
> Chris
>
>> Brian
>>
>>
>>
>> *From:* Govind Songara [mailto:[log in to unmask]]
>> *Sent:* 04 August 2011 11:29
>> *To:* Davies, Brian (STFC,RAL,ESC)
>> *Cc:* [log in to unmask]
>> *Subject:* Re: congestion control algorithm on disk servers.
>>
>>
>>
>> RHUL use the default one BIC,
>> What is recommendations.?
>>
>> On Thu, Aug 4, 2011 at 11:00 AM, <[log in to unmask]
>> <mailto:[log in to unmask]>> wrote:
>>
>> What are sites using?
>>
>> Who is using BIC?
>>
>> Who is using CUBIC?
>>
>> Who is using HTCP?
>>
>> Brian
>>
>>
>>
__________________________________________________
Dr Elena Korolkova
Email: [log in to unmask]
Tel.: +44 (0)114 2223553
Fax: +44 (0)114 2223555
Department of Physics and Astronomy
University of Sheffield
Sheffield, S3 7RH, United Kingdom
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