VPS is losing randomly network connection - puzzled why - HELP!!!

[Nick57]

Hi there, I have this strange error about losing network connection, the VPS is running fine and all over the sudden unexpected [randomly] the VPS is losing network connection.

I use cPanel WHM 11.38.1 (build 13) with CentOS v5.9.
VPS has 12GB memory and is hosted on Citrix Xenserver.

I have compared the network settings with another VPS on the same host, with identical memory and OS versions, both VPS are same except that the one who is losing connection has a lower PHP version and MySQL [but I am sure that is not relevant?]

Both VPS have identical kernel versions, so I am really puzzled why this VPS in particular is losing network connection, anyone out there had this before and is able to give advice?

Watching with a ping -t [ip] after a reboot it seems fine for hours.

In /var/log/messages i can see it is losing the connection:
named[2670]: no longer listening on 127.0.0.1#53
named[2670]: no longer listening on xxx.xxx.xxx.xxx#53 [*All IPs]

Another warning:

named[2667]: loading configuration from '/etc/named.conf'
Jul 23 12:11:45 xxx kernel: You need to implement a remote task_setrlimit in your security module and call it directly from this functionWARNING: at security/security.c:51 security_ops_task_setrlimit()
Jul 23 12:11:45 xxx kernel:
Jul 23 12:11:45 xxx kernel: Call Trace:
Jul 23 12:11:45 xxx kernel: [<ffffffff8031fea5>] security_ops_task_setrlimit+0x87/0x96
Jul 23 12:11:45 xxx kernel: [<ffffffff80298fb1>] do_prlimit+0xd7/0x1da
Jul 23 12:11:45 xxx kernel: [<ffffffff8029a0df>] sys_setrlimit+0x36/0x43
Jul 23 12:11:45 xxx kernel: [<ffffffff802602f9>] tracesys+0xab/0xb6
Jul 23 12:11:45 xxx kernel:




Thanks.

 

[cPanelMichael]

Hello

Have you checked with your VPS hosting provider or your data center to see if there are any network issues causing this problem?

Thank you.

 

[Nick57]

Hello

Have you checked with your VPS hosting provider or your data center to see if there are any network issues causing this problem?

Thank you.

Yes, as stated, both VPS are on same [Citrix Xenserver] Host and the other VPS runs fine.
I also got this morning after again rebooting the VPS an email with warning IPaliases failed!
So far twice happened after a cpanel update, perhaps indicating something is wrong with restarting services after the update?

 

[cPanelMichael]

You can open a support ticket so we can take a closer look and attempt to reproduce the issue:

Submit A Ticket

Post the ticket number here so we can update this thread with the outcome.

Thank you.

 

[Nick57]

Request ID: 4301583

 

[Nick57]

Update, removed the NetworkManager, although never used by me, I think it came with the default installation.
Keep fingers crossed the issue is solved now and customers happy again.

 

[Nick57]

Solved, the problem maker is Citrix Xenserver in combination with the BIOS C-state setting.

CTX127395 - Hosts Become Unresponsive with XenServer 5.6 and above on Nehalem and Westmere CPUs - Citrix Knowledge Center