Hello, currently I'm setting up my new home 24/7 server which has become an AMD Athlon system because of its energy efficience. Because XEN - due to its outdated kernel - does not work on my hardware, KVM was kind too fresh when I started my project and the license information of VirtualBox was not clear I decided to use UML.
To make it short: Everything works stable but way too slow. The effect is that in my opinion every larger memory allocation leads to heavy disk activity. E. g. dd if=/dev/zero of=/dev/null bs=128M count=1 where no disk I/O is done leads to heavy write access on the hosts harddisks (due to its typical access pattern on the hosts RAID1 system disks I can tell quite for sure that it's write access). After approx. 5s dd returns and states very low performance of about 8..14MB/s. When I use small blocks of about 1M and increase the count instead performace boosts a lot. The UML has enough memory (256M, ~190M free), the host itself has 6GB (well, I started with 2GB before I experimented with VirtualBox and a Windows installation - the problems existed from the beginning when the machine only had 2GB). Swap space is not used, even when I turn of all swap space on the host and the UML heavy disk access appears. For testing I moved the UML's file system to a separate disk, even then on the host's system disks heavy I/O happens every time I do this call. Any idea what the reason for this behaviour could be? With kind regards, Torsten Lang ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ User-mode-linux-user mailing list User-mode-linux-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-user
