| Re: Limiting CPU for tasks on HN ? [message #33714 is a reply to message #33188] |
Sun, 02 November 2008 19:05   |
seanfulton
Messages: 105
Registered: May 2007
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Senior Member |
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I am experiencing a similar problem. We moved our mail server from a physical machine with 2 G of RAM and 2 G of SWAP into a virtual machine with essentially the same resources.
Nightly backup causes the mail server activity to drop to nothing, causing back-ups and major issues. I have spent about a month trouble-shooting this and verified that there is nothing within the VE that is causing the hang up.
When I turn off the nightly backup, no problems. When I run one, everything hangs.
Two things I have noticed which are strange: there are no errors inside the VE, just more and more sendmail processes launching, but the old ones don't close.
Second, it is possible to allocate more RAM to a VE than the system has, causing the HN to crash. I opened up all of the memory settings for the VE until the HN crashed. Had to back off the settings to keep it up. I know when the machine was running on a physical machine, it would kill off processes as the system ran out of ram (and swap). This activity happens within the VE itself. But if you accidentally tell the VE it has 8 G available but it only has 6G, it will cause a kernel panic the HN once it exhausts the 6 G.
BTW: Nightly backup is vzdump to an NFS mount. THis is how I am set (2202 is the sendmail VE):
[root@gcn16 ~]# vzcpucheck -v
VEID CPUUNITS
-------------------------
0 1000
2202 100000
6005 1000
Current CPU utilization: 102000
Power of the node: 232811
[root@gcn16 ~]#
sean
[Updated on: Sun, 02 November 2008 19:07] Report message to a moderator |
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