Hello. We are having occasional issus with disk IO in our Xen guests. The wait IO can get very high (sometimes even 100%). The disk are NFS mounted from an Isilon cluster. I believe our Xen guests are not fully tuned. Basically my question is: For a Centos 5.x Xen DomU, what disk device drivers should I have loaded and is there anything else in particular I should pay attention to? xm info output: release : 2.6.18-194.3.1.el5xen version : #1 SMP Thu May 13 13:49:53 EDT 2010 machine : x86_64 nr_cpus : 16 nr_nodes : 1 cores_per_socket : 4 threads_per_core : 2 cpu_mhz : 2261 hw_caps : bfebfbff:28100800:00000000:00000340:009ce3bd:00000000:00000001:00000000 virt_caps : hvm total_memory : 32758 free_memory : 12166 node_to_cpu : node0:0-15 node_to_memory : node0:12166 xen_major : 3 xen_minor : 4 xen_extra : .2 xen_caps : xen-3.0-x86_64 xen-3.0-x86_32p hvm-3.0-x86_32 hvm-3.0-x86_32p hvm-3.0-x86_64 xen_scheduler : credit xen_pagesize : 4096 platform_params : virt_start=0xffff800000000000 xen_changeset : unavailable cc_compiler : gcc version 4.1.2 20080704 (Red Hat 4.1.2-44) cc_compile_by : root cc_compile_domain : gitco.tld cc_compile_date : Wed Nov 11 21:16:28 CET 2009 xend_config_format : 4 _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users