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Network Behavior [message #49980]

Tue, 16 July 2013 22:51

wpeckham
Messages: 6
Registered: March 2008
Location: West Virginia, USA

Junior Member

I used a fresh load of CentOS 6.3 (x86_64) for the host, used the install instructions from the OpenVZ.org site. The versions were the latest stable available today, 20120716. I dropped in a template and loaded 32-bit guest running CentOS 5.9. I fired up scp on another server sn transferred a file to the guest, and the transfer stalled, runnign about 10% of the speed I would have expected after the first few K.

Deciding
I had dome something wrong, I pulled down the latest CentOS 6.4 and installed a new host (also 64-bit) and dropped a guest there using CentOS 5 in 32-bit and tested it. The problem was WORSE! A 2K file transferred in seconds, a larger file stalled and NEVER COMPLETED.

I noted in both cases ssh connections worked fine, and thin odbc packets (small data requests) worked while larger ones broke the connection.

I am dropping back to CentOS 5 in 32-bit for the host, as I have many instances where that is working. I am curious thoug, if I did something wrong by mixing CentOS6 in 64bit as host with CentOS5 32-bit as guests, is this a problem with CentOS6, a problem with something in OpenVZ in the combination, or something I have not even considered?

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Re: Network Behavior [message #49986 is a reply to message #49980]

Wed, 17 July 2013 18:00

Paparaciz
Messages: 302
Registered: August 2009

Senior Member

do I understand you correctly:
you have 2 HN servers with centos6(64bit) and in both of them CT with centos5(32bit) and connection stalls between this CTs?

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Re: Network Behavior [message #49987 is a reply to message #49986]

Wed, 17 July 2013 19:01

wpeckham
Messages: 6
Registered: March 2008
Location: West Virginia, USA

Junior Member

Traffic stalls between the CT and anything external. the other CT, the remote host, I did not check between the HN and its CT.
Again, if the traffic is 'thin' you will never see the effect. Session over ssh work fine. I suspect telnet would be fine. It is anything where the volume of data is larger that triggers the issue. Since I was able to replicate it so easily (if unhappily) here, I suspect it is repeatable.

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Re: Network Behavior [message #49993 is a reply to message #49987]

Thu, 18 July 2013 17:56

wpeckham
Messages: 6
Registered: March 2008
Location: West Virginia, USA

Junior Member

UPDATE:: I reloaded one of the boxes with 32-bit CentOS 5.9 and installed OpenVZ, manually migrated the guest over, and there it performed perfectly. The problem seems ONLY to express on CentOS 6.3 and 6.4 64-bit hosts.

I have a 64-bit install of CentOS 5.9 running multiple CentOS 32-bit guests with no problem, so it is not simply a 32 on 64 issue. It seem specific to CentOS 6, though I have not tested enough to prove that it is limited to the 64-bit hosts, or 64-bit host with 32-bit container.

My search for known issues was not exhaustive, but I found nothing that stood out as quite like this. It occurs to me to ask if this problem is limited to MY servers! Were it general, I would think others would have detected it first.

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Re: Network Behavior [message #49999 is a reply to message #49980]

Fri, 19 July 2013 16:10

Paparaciz
Messages: 302
Registered: August 2009

Senior Member

I suggest to file bug report, give instructions how to reproduce and then it will be fixed.

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Re: Network Behavior [message #50000 is a reply to message #49999]

Fri, 19 July 2013 17:06

wpeckham
Messages: 6
Registered: March 2008
Location: West Virginia, USA

Junior Member

I always hesitate to do that in case it is a known issue, I hate causing development people duplication and distraction (having lived it for many years). I will take your advice and see if we can play.

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Re: Network Behavior [message #50001 is a reply to message #49980]

Fri, 19 July 2013 17:45

Paparaciz
Messages: 302
Registered: August 2009

Senior Member

I understand you, but because I currently don't have time to test and investigate issue I just recommended you best path to solve problem. that's why I suggessted to show how to reproduce bug.

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