Hi everybody, my background: I'm doing Xen since 10++ years, many years with DRBD for high availability, since some time I'm using preferable GlusterFS with FUSE as replicated storage, where I place the image-files for the vms. In my current project we started (successfully) with Xen/GlusterFS too, but because the provider, where we placed the servers, uses widely CEPH, we decided to switch too. Unfortunately I'm new to CEPH, but with help of a technician, we have running a 3 node CEPH-cluster now, that seems to work fine. Hardware: - Xeons, 24 Cores, 256 GB RAM, 2x 240 GB system-SSDs RAID1, 4x 1,92 TB data-SSDs (no RAID) Software we are using: - CentOS 7.5.1804 - Kernel: 4.9.86-30.el7 @centos-virt-xen-48 - Xen: 4.8.3-5.el7 @centos-virt-xen-48 - libvirt-xen: 4.1.0-2.xen48.el7 @centos-virt-xen-48 - Ceph: 2:12.2.5-0.el7 @Ceph CEPH itself works, Xen too and even libvirt (I'm quite new in this too, normally I use the XL-tools to manage my VMs) ;-) I can manually map an RBD and start a PV-VM via libvirt, after modifying the XML-config and defined the VM with libvirt. That is what happens: # virsh define xml/testvm3.xml Domain testvm3 defined from xml/testvm3.xml # virsh start --console testvm3 error: Failed to start domain testvm3 error: internal error: libxenlight failed to create new domain 'testvm3' xml/testvm3.xml: -> ... <devices> <disk type='network' device='disk'> <source protocol='rbd' name='devel-pool/testvm3.rbd'> <host name="10.20.30.1" port="6789"/> <host name="10.20.30.2" port="6789"/> <host name="10.20.30.3" port="6789"/> </source> <auth username='libvirt'> <secret type='ceph' uuid='07f3a0fe-9178-xxxxxxxxx'/> </auth> <target dev='xvda' bus='xen'/> </disk> ... Logs: /var/log/libvirt/libxl/libxl-driver.log: -> ... 2018-05-27 11:24:36.666+0000: libxl: libxl_bootloader.c:634:bootloader_finished: bootloader failed - consult logfile /var/log/xen/bootloader.14.log 2018-05-27 11:24:36.666+0000: libxl: libxl_exec.c:118:libxl_report_child_exitstatus: bootloader [183216] exited with error status 1 2018-05-27 11:24:36.667+0000: libxl: libxl_create.c:1259:domcreate_rebuild_done: cannot (re-)build domain: -3 /var/log/xen/bootloader.14.log: -> Traceback (most recent call last): File "/usr/lib64/xen/bin/pygrub", line 896, in <module> part_offs = get_partition_offsets(file) File "/usr/lib64/xen/bin/pygrub", line 113, in get_partition_offsets image_type = identify_disk_image(file) File "/usr/lib64/xen/bin/pygrub", line 56, in identify_disk_image fd = os.open(file, os.O_RDONLY) OSError: [Errno 2] No such file or directory: 'rbd:devel-pool/testvm3.rbd:id=libvirt:key=AQBThwFbGFRYFxxxxxxxxxxxxxxx==:auth_supported=cephx\\;none:mon_host=10.20.30.1\\:6789\\;10.20.30.2\\:6789\\;10.20.30.3\\:6789' So the Xen-Python-script, that searches for the kernel/bootloader of the VM, does not find the imagefile. But if I grab the above output and use it with qemu, it does find the blockdevice: # qemu-img info "rbd:devel-pool/testvm3.rbd:id=libvirt:key=AQBThwFbGFRYFxxxxxxxxxxxxxxx==:auth_supported=cephx\\;none:mon_host=10.20.30.1\\:6789\\;10.20.30.2\\:6789\\;10.20.30.3\\:6789" -> image: rbd:devel-pool/testvm3.rbd:id=libvirt:key=AQBThwFbGFRYFxxxxxxxxxxxxxxx==:auth_supported=cephx\;none:mon_host=10.20.30.1\:6789\;10.20.30.2\:6789\;10.20.30.3\:6789 file format: raw virtual size: 16G (17179869184 bytes) disk size: unavailable Thus it seems, that CEPH-auth works and the VM-XML-config is interpreted correct by libvirt. But the next step fails, when libvirt should pass the blockdevice to Xen? Anybody out there who uses a similar configuration? Any hints how to debug this? Unfortunately I do not have anymore logs to look at. Thank you very much, -- Kind regards, thg