def mount_imgfn(imgname):
"""
Link vm image with an nbd device.
Parameters
----------
imgname: str
Full path of the image file.
Returns
-------
str: Device name on success, raises an exception otherwise.
"""
#
# create nbd devices
_logger.debug('__ Running mount image file %s.' % imgname)
result_msg(msg='Load nbd')
if not system_tools.create_nbd():
raise OciMigrateException('Failed ot load nbd module')
else:
_logger.debug('nbd module loaded')
#
# find free nbd device
result_msg(msg='Find free nbd device')
devpath = system_tools.get_free_nbd()
_logger.debug('Device %s is free.' % devpath)
#
# link img with first free nbd device
result_msg(msg='Mount image %s' % imgname, result=True)
_, nbcols = terminal_dimension()
try:
mountwait = ProgressBar(nbcols, 0.2, progress_chars=['mounting image'])
mountwait.start()
qemucmd = ['-c', devpath, imgname]
pause_msg(qemucmd)
qemunbd_ret = system_tools.exec_qemunbd(qemucmd)
if qemunbd_ret == 0:
time.sleep(5)
_logger.debug('qemu-nbd %s succeeded' % qemucmd)
return devpath
else:
_logger.critical('\n Failed to create nbd devices: %d' %
qemunbd_ret)
raise Exception('Failed to create nbd devices: %d' % qemunbd_ret)
except Exception as e:
_logger.critical('\n Something wrong with creating nbd devices: %s' %
str(e))
raise OciMigrateException('Unable to create nbd devices: %s' % str(e))
finally:
if system_tools.is_thread_running(mountwait):
mountwait.stop()
def unmount_imgfn(devname):
"""
Unlink a device.
Parameters
----------
devname: str
The device name
Returns
-------
bool: True on succes, raise an exception otherwise.
"""
_logger.debug('__ Unmount %s' % devname)
try:
#
# release device
qemucmd = ['-d', devname]
pause_msg(qemucmd)
qemunbd_ret = system_tools.exec_qemunbd(qemucmd)
if qemunbd_ret == 0:
_logger.debug('qemu-nbd %s succeeded: %d' % (qemucmd, qemunbd_ret))
else:
raise Exception('%s returned %d' % (qemucmd, qemunbd_ret))
#
# clear lvm cache, if necessary.
if system_tools.exec_pvscan(['--cache']):
_logger.debug('lvm cache updated')
else:
_logger.error(' Failed to clear LVM cache.')
raise OciMigrateException('Failed to clear LVM cache.')
#
# remove nbd module
if not system_tools.rm_nbd():
raise OciMigrateException('Failed to remove nbd module.')
else:
_logger.debug('Successfully removed nbd module.')
except Exception as e:
_logger.critical(' Something wrong with removing nbd devices: %s' %
str(e))
raise OciMigrateException('\nSomething wrong with removing nbd '
'devices: %s' % str(e))
return True