root@ubuntu:~# xe vbd-param-list uuid=71a80e20-2cea-9bcb-0c72-d6e39bb4c5c0 uuid ( RO) : 71a80e20-2cea-9bcb-0c72-d6e39bb4c5c0 vm-uuid ( RO): 246e6121-aa22-17da-a212-ba2b2103f5bf vm-name-label ( RO): s-8-VM vdi-uuid ( RO): ef49891a-9774-4d6f-bbbb-31e9a52f4815 vdi-name-label ( RO): systemvm.iso allowed-operations (SRO): pause; unpause; attach; eject; unplug_force; unplug current-operations (SRO): empty ( RO): false device ( RO): xvdd userdevice ( RW): 3 bootable ( RW): false mode ( RW): RO type ( RW): CD unpluggable ( RW): true currently-attached ( RO): true attachable ( RO): true storage-lock ( RO): false status-code ( RO): 0 status-detail ( RO): qos_algorithm_type ( RW): qos_algorithm_params (MRW): qos_supported_algorithms (SRO): other-config (MRW): io_read_kbs ( RO): <unknown> io_write_kbs ( RO): <unknown> root@ubuntu:~# xe vdi-param-list uuid=ef49891a-9774-4d6f-bbbb-31e9a52f4815 uuid ( RO) : ef49891a-9774-4d6f-bbbb-31e9a52f4815 name-label ( RW): systemvm.iso name-description ( RW): is-a-snapshot ( RO): false snapshot-of ( RO): <not in database> snapshots ( RO): snapshot-time ( RO): 19700101T00:00:00Z allowed-operations (SRO): clone; snapshot current-operations (SRO): sr-uuid ( RO): 481f1c9d-863c-fcf1-225e-75eec166133e sr-name-label ( RO): XenServer Tools vbd-uuids (SRO): 71a80e20-2cea-9bcb-0c72-d6e39bb4c5c0 crashdump-uuids (SRO): virtual-size ( RO): 14280704 physical-utilisation ( RO): 14280704 location ( RO): systemvm.iso type ( RO): User sharable ( RO): false read-only ( RO): true storage-lock ( RO): false managed ( RO): true parent ( RO): <not in database> missing ( RO): false other-config (MRW): xenstore-data (MRO): sm-config (MRO): xs-tools: true on-boot ( RW): persist allow-caching ( RW): false metadata-latest ( RO): false metadata-of-pool ( RO): <not in database> tags (SRW): root@ubuntu:~# xe sr-list uuid=481f1c9d-863c-fcf1-225e-75eec166133e uuid ( RO) : 481f1c9d-863c-fcf1-225e-75eec166133e name-label ( RW): XenServer Tools name-description ( RW): XenServer Tools ISOs host ( RO): ubuntu type ( RO): iso content-type ( RO): iso On syslog, I see the following errors: Jun 6 14:38:55 ubuntu xapi: [20120606T21:38:55.343Z| info|ubuntu|7563 UNIX /var/lib/xcp/xapi|VBD.create R:f4d814ea3dea|audit] (''trackid=bd8429fa72a024f3edc49659f7aa9941'' ''LOCAL_SUPERUSER'' ''root'' ''ALLOWED'' ''OK'' ''API'' ''VBD.create'' ((''VM'' ''s-8-VM'' ''246e6121-aa22-17da-a212-ba2b2103f5bf'' ''OpaqueRef:ecf9d238-7bc4-309d-17fb-c9cddcf41bdf'') (''VDI'' ''systemvm.iso'' ''ef49891a-9774-4d6f-bbbb-31e9a52f4815'' ''OpaqueRef:a672d623-b8b3-e4f2-d8df-c5caf2d4d381''))) Jun 6 14:38:55 ubuntu udevd[26831]: kernel-provided name ''blktap0'' and NAME= ''xen/blktap-2/blktap0'' disagree, please use SYMLINK+= or change the kernel to provide the proper name Jun 6 14:38:55 ubuntu tapdisk[30921]: tapdisk-control: init, 10 x 4k buffers Jun 6 14:38:55 ubuntu tapdisk[30921]: I/O queue driver: lio Jun 6 14:38:55 ubuntu tapdisk[30921]: tapdisk-log: started, level 0 Jun 6 14:38:55 ubuntu tapdisk[30921]: received ''attach'' message (uuid = 0) Jun 6 14:38:55 ubuntu tapdisk[30921]: sending ''attach response'' message (uuid = 0) Jun 6 14:38:55 ubuntu tapdisk[30921]: received ''open'' message (uuid = 0) Jun 6 14:38:55 ubuntu tapdisk[30921]: block-aio open(''/usr/share/xcp/packages/iso/systemvm.iso'') Jun 6 14:38:55 ubuntu tapdisk[30921]: open(/usr/share/xcp/packages/iso/systemvm.iso) with O_DIRECT Jun 6 14:38:55 ubuntu tapdisk[30921]: Image size: #012#011pre sector_shift [14280704]#012#011post sector_shift [27892] Jun 6 14:38:55 ubuntu tapdisk[30921]: opened image /usr/share/xcp/packages/iso/systemvm.iso (1 users, state: 0x00000003, type: 0, ro) Jun 6 14:38:55 ubuntu tapdisk[30921]: VBD CHAIN: Jun 6 14:38:55 ubuntu tapdisk[30921]: /usr/share/xcp/packages/iso/systemvm.iso: type:aio(0) storage:n/a(-1) Jun 6 14:38:55 ubuntu tapdisk[30921]: bdev: capacity=27892 sector_size=512/512 flags=0 Jun 6 14:38:55 ubuntu tapdisk[30921]: sending ''open response'' message (uuid = 0) Jun 6 14:38:55 ubuntu kernel: [11434.498009] block tda: sector-size: 512/512+0 capacity: 27892 discard: 0+0 flush: 0x0 Jun 6 14:38:55 ubuntu kernel: [11434.651214] xen-blkback:ring-ref 2351, event-channel 8, protocol 2 (x86_32-abi) Jun 6 14:38:55 ubuntu logger: /etc/xen/scripts/block: add XENBUS_PATH=backend/vbd/8/51760 Jun 6 14:38:55 ubuntu logger: /etc/xen/scripts/block: Writing backend/vbd/8/51760/hotplug-error /dev/sm/backend/481f1c9d-863c-fcf1-225e-75eec166133e/ef49891a-9774-4d6f-bbbb-31e9a52f4815 does not exist. backend/vbd/8/51760/hotplug-status error to xenstore. Jun 6 14:38:55 ubuntu xapi: [20120606T21:38:55.946Z| info|ubuntu|7563 UNIX /var/lib/xcp/xapi|VBD.plug R:395bed0c1b4d|audit] (''trackid=bd8429fa72a024f3edc49659f7aa9941'' ''LOCAL_SUPERUSER'' ''root'' ''ALLOWED'' ''OK'' ''API'' ''VBD.plug'' ((''self'' '''' ''71a80e20-2cea-9bcb-0c72-d6e39bb4c5c0'' ''OpaqueRef:b8c902b1-e003-b2a9-6811-5e3463502e93''))) Jun 6 14:38:55 ubuntu logger: /etc/xen/scripts/block: /dev/sm/backend/481f1c9d-863c-fcf1-225e-75eec166133e/ef49891a-9774-4d6f-bbbb-31e9a52f4815 does not exist. Jun 6 14:39:42 ubuntu xapi: [20120606T21:39:42.500Z| info|ubuntu|7602 UNIX /var/lib/xcp/xapi|VBD.assert_attachable R:8c1e29a2c394|audit] (''trackid=b0d2942c096fec716132a3bbed0d8bf6'' ''LOCAL_SUPERUSER'' ''root'' ''ALLOWED'' ''OK'' ''API'' ''VBD.assert_attachable'' ((''self'' '''' ''71a80e20-2cea-9bcb-0c72-d6e39bb4c5c0'' ''OpaqueRef:b8c902b1-e003-b2a9-6811-5e3463502e93''))) Jun 6 14:39:42 ubuntu xapi: [20120606T21:39:42.516Z| info|ubuntu|7602 UNIX /var/lib/xcp/xapi|VM.query_data_source D:91a338ea8c6e|audit] (''trackid=b0d2942c096fec716132a3bbed0d8bf6'' ''LOCAL_SUPERUSER'' ''root'' ''ALLOWED'' ''ERROR:INVALID_VALUE: [ data-source; vbd_xvdd_read ]'' ''API'' ''VM.query_data_source'' ((''self'' ''s-8-VM'' ''246e6121-aa22-17da-a212-ba2b2103f5bf'' ''OpaqueRef:ecf9d238-7bc4-309d-17fb-c9cddcf41bdf''))) Jun 6 14:39:42 ubuntu xapi: [20120606T21:39:42.523Z| info|ubuntu|7602 UNIX /var/lib/xcp/xapi|VM.query_data_source D:15a5e5856b64|audit] (''trackid=b0d2942c096fec716132a3bbed0d8bf6'' ''LOCAL_SUPERUSER'' ''root'' ''ALLOWED'' ''ERROR:INVALID_VALUE: [ data-source; vbd_xvdd_write ]'' ''API'' ''VM.query_data_source'' ((''self'' ''s-8-VM'' ''246e6121-aa22-17da-a212-ba2b2103f5bf'' ''OpaqueRef:ecf9d238-7bc4-309d-17fb-c9cddcf41bdf''))) Jun 6 14:41:28 ubuntu kernel: [11587.004380] ISO 9660 Extensions: RRIP_1991A Jun 6 14:45:00 ubuntu xapi: [20120606T21:45:00.997Z| info|ubuntu|7616 UNIX /var/lib/xcp/xapi|VBD.assert_attachable R:a17ba41316d0|audit] (''trackid=6136dfb0c82ceaeb530a37c02df18655'' ''LOCAL_SUPERUSER'' ''root'' ''ALLOWED'' ''OK'' ''API'' ''VBD.assert_attachable'' ((''self'' '''' ''71a80e20-2cea-9bcb-0c72-d6e39bb4c5c0'' ''OpaqueRef:b8c902b1-e003-b2a9-6811-5e3463502e93''))) Jun 6 14:45:01 ubuntu xapi: [20120606T21:45:01.005Z| info|ubuntu|7616 UNIX /var/lib/xcp/xapi|VM.query_data_source D:98177990f4d3|audit] (''trackid=6136dfb0c82ceaeb530a37c02df18655'' ''LOCAL_SUPERUSER'' ''root'' ''ALLOWED'' ''ERROR:INVALID_VALUE: [ data-source; vbd_xvdd_read ]'' ''API'' ''VM.query_data_source'' ((''self'' ''s-8-VM'' ''246e6121-aa22-17da-a212-ba2b2103f5bf'' ''OpaqueRef:ecf9d238-7bc4-309d-17fb-c9cddcf41bdf''))) Jun 6 14:45:01 ubuntu xapi: [20120606T21:45:01.009Z| info|ubuntu|7616 UNIX /var/lib/xcp/xapi|VM.query_data_source D:769d4729e23a|audit] (''trackid=6136dfb0c82ceaeb530a37c02df18655'' ''LOCAL_SUPERUSER'' ''root'' ''ALLOWED'' ''ERROR:INVALID_VALUE: [ data-source; vbd_xvdd_write ]'' ''API'' ''VM.query_data_source'' ((''self'' ''s-8-VM'' ''246e6121-aa22-17da-a212-ba2b2103f5bf'' ''OpaqueRef:ecf9d238-7bc4-309d-17fb-c9cddcf41bdf''))) 56069,1 Inside guest, I see errors like "XENBUS: Timeout connecting to device: device/vbd/5170(local state 3, remote state 2)" . Any hint how to debug this issue?