On 22.07.2013 11:58, Daniel P. Berrange wrote: > On Fri, Jul 12, 2013 at 05:13:56PM +0200, Viktor Mihajlovski wrote: >> The alias for hostdevs of type SCSI can be too long for QEMU if >> larger LUNs are encountered. Here's a real life example: >> >> <hostdev mode='subsystem' type='scsi' managed='no'> >> <source> >> <adapter name='scsi_host0'/> >> <address bus='0' target='19' unit='1088634913'/> >> </source> >> <address type='drive' controller='0' bus='0' target='0' unit='0'/> >> </hostdev> >> >> this results in a too long drive id, resulting in QEMU yelling >> >> Property 'scsi-generic.drive' can't find value 'drive-hostdev-scsi_host0-0-19-1088634913' >> >> This commit changes the alias back to the default hostdev$(index) >> scheme. >> >> Signed-off-by: Viktor Mihajlovski <mihajlov@xxxxxxxxxxxxxxxxxx> >> --- >> >> Actually this is highlighting a larger issue. Apparently QEMU ids >> are limited to a length of 32 bytes. This means that SCSI based >> drives are also in danger to exceed this limit. >> We should consider to use a drive index for controller-attached >> disks for alias generation instead of the verbose >> drive-$bustype-$busaddress schema. > > Urgh that sucks. I had no idea QEMU would impose such an arbitrary > length limitation for something like this. > >> >> src/qemu/qemu_command.c | 10 +--------- >> .../qemuxml2argv-hostdev-scsi-boot.args | 4 ++-- >> .../qemuxml2argv-hostdev-scsi-lsi.args | 4 ++-- >> .../qemuxml2argv-hostdev-scsi-readonly.args | 4 ++-- >> .../qemuxml2argv-hostdev-scsi-virtio-scsi.args | 4 ++-- >> 5 files changed, 9 insertions(+), 17 deletions(-) >> > > ACK > > There's no back compatibility issues, since we store the aliases for running > guests in the state XML. Thus this will only affect newly launched guests > > Daniel > Pushed now. Michal -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list