On 08/16/2012 04:57 PM, Avi Kivity wrote: Hi Avi, No, there was no reason and we disabled it there too. Interestingly, the buffer size did not go down significantly, even when manually flushing the pages using /proc/sys/vm/drop_caches (3), the buffer size did not go down. Finally, after rebooting the host, buffer size was back to normal again and when all caches were disabled, we were also able to manually drop the buffered pages. However, after 2 weeks or so, we encountered significant instabilities in the system. Inside the guest OS, the load went up like crazy (way past 30) and the guest was virtually unusable. Checking the host: buffer size, load, memory, I/O was all in a well defined range. When rebooting the guest OS, the problem manifested again after about 20-30mins (reproducible a couple of times). The only thing that worked to stop this (I am afraid only for a couple of weeks or so), was rebooting the host system. On the guest and the host there was nothing suspicious in the logs or dmesg output. Best regards, Martin -- -------------------------------------------------------------------- Martin Wawro | Digital Medics GmbH Managing Director | Otto-Hahn-Str. 15, 44227 Dortmund, Germany Tel. +49-231-9742-6622 | Fax: +49-231-9742-6623 Key: 0xB0A225BD | Registered at AG Dortmund, HRB 19360 --------------------------------------------------------------------