Hi All, One more weird issue, this works on old xen but fails on 4.4: xendev01 ~ # mkdir /mnt/test xendev01 ~ # mount -t tmpfs - /mnt/test xendev01 ~ # dd if=/dev/null of=/mnt/test/disk seek=100M bs=1 0+0 records in 0+0 records out 0 bytes (0 B) copied, 0.000201809 s, 0.0 kB/s xendev01 ~ # /usr/sbin/xl block-attach nathannx "file:/mnt/test/disk" "xvdd4" DEBUG libxl__blktap_devpath 37 aio:/mnt/test/disk DEBUG libxl__blktap_devpath 40 /dev/xen/blktap-2/tapdev20 xendev01 ~ # xl block-detach nathannx 51764 DEBUG libxl__device_destroy_tapdisk 66 type=aio:/mnt/test/disk disk=:/mnt/test/disk xendev01 ~ # mount -o remount,ro /mnt/test xendev01 ~ # /usr/sbin/xl block-attach nathannx "file:/mnt/test/disk" "xvdd4" DEBUG libxl__blktap_devpath 37 aio:/mnt/test/disk libxl: error: libxl.c:2149:device_disk_add: failed to get blktap devpath for 0xd3abd0 libxl: error: libxl.c:1727:device_addrm_aocomplete: unable to (null) device libxl_device_disk_add failed. I'm not sure why xen would care if the disk is writable? Would be nice to be able to mount these since many NFS storage arrays provide read only access to snapshots. - Nathan -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.centos.org/pipermail/centos-virt/attachments/20150312/94efcce9/attachment-0003.html>