Hi Baptiste, In my opinion it's all about your VM/ATS settings. Can you post these clues:
cat /proc/interrupts cat etc/trafficserver/records.config | grep thread cat etc/trafficserver/storage.config | grep dev lshw -c disk -c volume Cheers JT From: Jan-Frode Myklebust <janfr...@tanso.net>; To: <dev@trafficserver.apache.org>; Subject: Re: TrafficServer and IO/Wait Sent: Wed, Jun 4, 2014 10:45:27 AM On Wed, Jun 04, 2014 at 11:28:07AM +0200, Jean Baptiste Favre wrote: > Hello, > Each VM has 4GB memory. > > traffic_line -r proxy.config.cache.ram_cache.size gives 2147483648 I would consider increasing proxy.config.cache.ram_cache.size to at least 3GB on your 4GB VMs. Assuming ATS will have better knowledge about what to keep in memory than the linux page cache. And maybe give the VMs lots of more memory so that you can increase the ram_cache.size further. I try to make sure ATS can keep everything in memory -- memory is cheap, disk IOPS is slow and expensive. -jf
