| Re: why buffers cached is always 0 in VPS/VE? [message #32930 is a reply to message #32925] |
Tue, 09 September 2008 08:04   |
tukey
Messages: 10
Registered: March 2008
Location: China
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Junior Member |
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| finist wrote on Tue, 09 September 2008 03:26 |
| Quote: |
Yes, there are failcounters. Starting tomcat is OK, it just happens when I try to shutdown tomcat.
384MB is not enough for tomcat and mysql in a VE, while it is enough in a physical machine(no swap)?
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Look, there is slightly different mechanisms in memory handling on Hardware Node and inside a Container.
if you have only 384Mb RAM on a Hardware Node and no swap - you'll be able to alloc 1Gb of memory in your problem. Without any problem. But if you later try to use that memory - read/write something from/to it, the process will be killed.
Inside a Container such a malloc of 1Gb will fail from the very beginning on an allocation stage - not actual using.
i think tomcat just allocs quite a lot of memory which does not really use - that's why it runs ok on a hardware node but fails inside a Container.
To gain the same functionality inside a Container you need to increase the privvmpages, but set the oomguarpages to 384Mb. In that case a program will be able to allocate a lot of RAM, but in case of global memory shortage on the node (if that process will try to use all allocated memory) - the process will be killed.
Hope that helps.
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Konstantin
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Thank you for your explaination. It makes me more clear.
Anyway, the buffers and cached will be just always kept as 0, because of the differenct memory allocation mechanisms between hardware node and VE. Am I right?
[Updated on: Tue, 09 September 2008 08:06] Report message to a moderator |
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