Dear All, I'm very new Gluster FS user.... ...and apologize for my very poor english! :-) I have installed Gluster FS v. 1.3.12 on 2 server with Debian 4.05, in AFR with client side replication, explained in this page: http://www.gluster.org/docs/index.php/Setting_up_AFR_on_two_servers_with_client_side_replication Tested to work! :-) Now, my idea: Use a Xen Hypervisor with image disk data for DomU machines on Gluster FS repository In my Gluster FS client machine (based on Centos 5.2), I have create a DomU machine with image file stored in local disk (/var/lib/xen/images/), Called "Debian4" O.K., start and finish installation without problems! Now, I have moved image file from /val/lib/xen/images/ to my GlusterFS directory (/mnt/glusterfs/) O.k., checked that image file, I'm go to modify DomU configuration wit new image disk path.... First setting: disk = [ 'file:/mnt/glusterfs/debian40.img,hda1,w' ] Start DomU, I retry this error: xend.err 'Device 768 (vbd) could not be connected. losetup /dev/loop0 /mnt/glusterfs/debian40.img failed' Into log explained error is: domid: 22 qemu: the number of cpus is 1 Watching /local/domain/22/logdirty/next-active xs_read(): vncpasswd get error. /vm/353e360e-bcdd-f237-595e-85013704aad7/vncpasswd. char device redirected to /dev/pts/4 qemu_map_cache_init nr_buckets = 10000 shared page at pfn 1ffff buffered io page at pfn 1fffd xs_read(/vm/353e360e-bcdd-f237-595e-85013704aad7/rtc/timeoffset): read error I/O request not ready: 0, ptr: 0, port: 0, data: 0, count: 0, size: 0 Triggered log-dirty buffer switch Second setting: disk = [ 'tap:aio:/mnt/glusterfs/debian40.img,hda1,w' ] Machine start and stop Into log explained error is: qemu: could not open hard disk image 'aio:/mnt/glusterfs/debian40-dnsldap.img' Watching /local/domain/21/logdirty/next-active xs_read(): vncpasswd get error. /vm/353e360e-bcdd-f237-595e-85013704aad7/vncpasswd. char device redirected to /dev/pts/4 qemu_map_cache_init nr_buckets = 10000 shared page at pfn 1ffff buffered io page at pfn 1fffd xs_read(/vm/353e360e-bcdd-f237-595e-85013704aad7/rtc/timeoffset): read error I/O request not ready: 0, ptr: 0, port: 0, data: 0, count: 0, size: 0 Triggered log-dirty buffer switch O.k., people have a solution? Many Thanks, Enrico Valsecchi