Hi, I just ran an hdparm on a PV domain after I experienced severe I/O issues on a network share. Basically Xen 3.1 domU disk performance is about 1/15th that of the dom0 and really quite poor. dom0: /dev/vg0/sisko2-disk: Timing cached reads: 5870 MB in 1.99 seconds = 2942.59 MB/sec Timing buffered disk reads: 184 MB in 3.01 seconds = 61.22 MB/sec domU (same disk): /dev/sda1: Timing cached reads: 6392 MB in 1.99 seconds = 3204.37 MB/sec Timing buffered disk reads: 16 MB in 3.50 seconds = 4.57 MB/sec The network I/O is simplarly afflicted, and runs 25 times worse than native: dom0->real machine: Recv Send Send Socket Socket Message Elapsed Size Size Size Time Throughput bytes bytes bytes secs. 10^6bits/sec 8192 16384 16384 10.00 830.36 domu->real machine: Recv Send Send Socket Socket Message Elapsed Size Size Size Time Throughput bytes bytes bytes secs. 10^6bits/sec 8192 16384 16384 10.15 30.98 dom0->domu: Recv Send Send Socket Socket Message Elapsed Size Size Size Time Throughput bytes bytes bytes secs. 10^6bits/sec 87380 16384 16384 10.02 35.85 domu->domu: Recv Send Send Socket Socket Message Elapsed Size Size Size Time Throughput bytes bytes bytes secs. 10^6bits/sec 87380 16384 16384 10.01 33.72 As is clear both network and disk performance are simply unnaceptable, even for test machines. I''ve tried pretty much every tweak that I can find and can''t make any difference to it. Currently the only thing keeping vmware server away is its linux version is 32bit only.. Any ideas? Tony _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users