I have been running both xen-86_64 and xen-86 on a Fujitsu-Siemens RX300 I tested the write-performance of a linux guest. The machine is configured with an LSI Megaraid Controller, Model LD 1 RAID0 139G, Rev 516D. Then Version of xen is 3.0.3 When doing "dd if=/dev/zero of=/dev/sdb1 bs=64k count=10000", I got a through- put of about 3.6 Megabytes per second. Device "sdb1" on the client was connected to sdb12 on the backend which was a slice on the disk controlled by the megaraid device. When doing the corresponding "dd" command on the privileged domain I got a througbut of about 25 Megabytes per second. I installed Xen on another machine only capable of running 32-bit code. I did similar tests and got ( partially due to a faster disk ) throughputs of 35Megabytes per second from the client and about 40 MB/s from the priviledged domain in respective tests. I suspected that the problem was probably related to the 64-bit Version but after installing it on the Rx300 I got exactly the same results. In a final test I connecte a USB-disk to the RX300 and got a throughput of 25 MB/sec onto that disk. I suspect that Xen is cooperating quite inefficiently with the controller. I found out that Writing speed was much faster when using a file-based VBD, even when the Systems Memory was significantly smaller than the amount of transfered data ( I limited domain0''s Memory to 384 MB and wrote 3 GB ). But this is not a solution because on the other System the process of writing permanently activated the oom-killer in domain0 and crashed the entire system within a few minutes. Preventing it from killing xen-related processes kept the System up, but it did no longer respond to external requests of the net. Reading throughput on the client domain was about the same as in domain 0 _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel