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This is a chart of memory usage in my AWS instance of Ubuntu 8 server, which is configured as a LAMP server. I've had a problem with this server locking up about once a month, and looking at the memory chart, I can see the cache slowly taking over available memory. Will it stop at some point, or just keep growing until it locks up the server - in other words, is this normal?

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share|improve this question – Zoredache Dec 31 '10 at 5:20
up vote 1 down vote accepted

Buffers and Cache look like they are doing what I would expect. Cache will continue to grow until 100% of your memory is being used. This is normal behavior as unused ram is wasted ram. Cache is released as other things need memory so this shouldn't force any low memory situation on any running applications.

What makes you suspect that your problem is with memory? It looks like you have plenty of unused memory there.

share|improve this answer
I don't have a reason to blame memory, just grasping at straws here. Not a sysadmin so the chart above looked suspicious enough to warrant investigation. – mattloaf1 Dec 30 '10 at 18:00
@mattloaf1 Fair enough. The system here appears to be using memory in a normal way. I would start by looking in your log files for messages just before the last time it locked up and see if that sheds any light on your problem. – 3dinfluence Dec 30 '10 at 18:14

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