ceph/src/ceph-volume/ceph_volume/devices/lvm/zap.py

   1 import argparse
   2 import logging
   3
   4 from textwrap import dedent
   5
   6 from ceph_volume import decorators, terminal, process
   7 from ceph_volume.api import lvm as api
   8
   9 logger = logging.getLogger(__name__)
  10
  11
  12 def wipefs(path):
  13     """
  14     Removes the filesystem from an lv or partition.
  15     """
  16     process.run([
  17         'sudo',
  18         'wipefs',
  19         '--all',
  20         path
  21     ])
  22
  23
  24 def zap_data(path):
  25     """
  26     Clears all data from the given path. Path should be
  27     an absolute path to an lv or partition.
  28
  29     10M of data is written to the path to make sure that
  30     there is no trace left of any previous Filesystem.
  31     """
  32     process.run([
  33         'dd',
  34         'if=/dev/zero',
  35         'of={path}'.format(path=path),
  36         'bs=1M',
  37         'count=10',
  38     ])
  39
  40
  41 class Zap(object):
  42
  43     help = 'Removes all data and filesystems from a logical volume or partition.'
  44
  45     def __init__(self, argv):
  46         self.argv = argv
  47
  48     @decorators.needs_root
  49     def zap(self, args):
  50         device = args.device
  51         lv = api.get_lv_from_argument(device)
  52         if lv:
  53             # we are zapping a logical volume
  54             path = lv.lv_path
  55         else:
  56             # we are zapping a partition
  57             #TODO: ensure device is a partition
  58             path = device
  59
  60         logger.info("Zapping: %s", path)
  61         terminal.write("Zapping: %s" % path)
  62
  63         wipefs(path)
  64         zap_data(path)
  65
  66         if lv:
  67             # remove all lvm metadata
  68             lv.clear_tags()
  69
  70         terminal.success("Zapping successful for: %s" % path)
  71
  72     def main(self):
  73         sub_command_help = dedent("""
  74         Zaps the given logical volume or partition. If given a path to a logical
  75         volume it must be in the format of vg/lv. Any filesystems present
  76         on the given lv or partition will be removed and all data will be purged.
  77
  78         However, the lv or partition will be kept intact.
  79
  80         Example calls for supported scenarios:
  81
  82           Zapping a logical volume:
  83
  84               ceph-volume lvm zap {vg name/lv name}
  85
  86           Zapping a partition:
  87
  88               ceph-volume lvm zap /dev/sdc1
  89
  90         """)
  91         parser = argparse.ArgumentParser(
  92             prog='ceph-volume lvm zap',
  93             formatter_class=argparse.RawDescriptionHelpFormatter,
  94             description=sub_command_help,
  95         )
  96
  97         parser.add_argument(
  98             'device',
  99             metavar='DEVICE',
 100             nargs='?',
 101             help='Path to an lv (as vg/lv) or to a partition like /dev/sda1'
 102         )
 103         if len(self.argv) == 0:
 104             print(sub_command_help)
 105             return
 106         args = parser.parse_args(self.argv)
 107         self.zap(args)