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 from ceph_volume.util import system
   9
  10 logger = logging.getLogger(__name__)
  11 mlogger = terminal.MultiLogger(__name__)
  12
  13
  14 def wipefs(path):
  15     """
  16     Removes the filesystem from an lv or partition.
  17     """
  18     process.run([
  19         'wipefs',
  20         '--all',
  21         path
  22     ])
  23
  24
  25 def zap_data(path):
  26     """
  27     Clears all data from the given path. Path should be
  28     an absolute path to an lv or partition.
  29
  30     10M of data is written to the path to make sure that
  31     there is no trace left of any previous Filesystem.
  32     """
  33     process.run([
  34         'dd',
  35         'if=/dev/zero',
  36         'of={path}'.format(path=path),
  37         'bs=1M',
  38         'count=10',
  39     ])
  40
  41
  42 class Zap(object):
  43
  44     help = 'Removes all data and filesystems from a logical volume or partition.'
  45
  46     def __init__(self, argv):
  47         self.argv = argv
  48
  49     @decorators.needs_root
  50     def zap(self, args):
  51         device = args.device
  52         lv = api.get_lv_from_argument(device)
  53         if lv:
  54             # we are zapping a logical volume
  55             path = lv.lv_path
  56         else:
  57             # we are zapping a partition
  58             #TODO: ensure device is a partition
  59             path = device
  60
  61         mlogger.info("Zapping: %s", path)
  62
  63         # check if there was a pv created with the
  64         # name of device
  65         pv = api.get_pv(pv_name=device)
  66         if pv:
  67             vg_name = pv.vg_name
  68             lv = api.get_lv(vg_name=vg_name)
  69
  70         if lv:
  71             osd_path = "/var/lib/ceph/osd/{}-{}".format(lv.tags['ceph.cluster_name'], lv.tags['ceph.osd_id'])
  72             if system.path_is_mounted(osd_path):
  73                 mlogger.info("Unmounting %s", osd_path)
  74                 system.unmount(osd_path)
  75
  76         if args.destroy and pv:
  77             logger.info("Found a physical volume created from %s, will destroy all it's vgs and lvs", device)
  78             vg_name = pv.vg_name
  79             mlogger.info("Destroying volume group %s because --destroy was given", vg_name)
  80             api.remove_vg(vg_name)
  81             mlogger.info("Destroying physical volume %s because --destroy was given", device)
  82             api.remove_pv(device)
  83         elif args.destroy and not pv:
  84             mlogger.info("Skipping --destroy because no associated physical volumes are found for %s", device)
  85
  86         wipefs(path)
  87         zap_data(path)
  88
  89         if lv and not pv:
  90             # remove all lvm metadata
  91             lv.clear_tags()
  92
  93         terminal.success("Zapping successful for: %s" % path)
  94
  95     def main(self):
  96         sub_command_help = dedent("""
  97         Zaps the given logical volume, raw device or partition for reuse by ceph-volume.
  98         If given a path to a logical volume it must be in the format of vg/lv. Any
  99         filesystems present on the given device, vg/lv, or partition will be removed and
 100         all data will be purged.
 101
 102         If the logical volume, raw device or partition is being used for any ceph related
 103         mount points they will be unmounted.
 104
 105         However, the lv or partition will be kept intact.
 106
 107         Example calls for supported scenarios:
 108
 109           Zapping a logical volume:
 110
 111               ceph-volume lvm zap {vg name/lv name}
 112
 113           Zapping a partition:
 114
 115               ceph-volume lvm zap /dev/sdc1
 116
 117         If the --destroy flag is given and you are zapping a raw device or partition
 118         then all vgs and lvs that exist on that raw device or partition will be destroyed.
 119
 120         This is especially useful if a raw device or partition was used by ceph-volume lvm create
 121         or ceph-volume lvm prepare commands previously and now you want to reuse that device.
 122
 123         For example:
 124
 125           ceph-volume lvm zap /dev/sda --destroy
 126
 127         If the --destroy flag is given and you are zapping an lv then the lv is still
 128         kept intact for reuse.
 129
 130         """)
 131         parser = argparse.ArgumentParser(
 132             prog='ceph-volume lvm zap',
 133             formatter_class=argparse.RawDescriptionHelpFormatter,
 134             description=sub_command_help,
 135         )
 136
 137         parser.add_argument(
 138             'device',
 139             metavar='DEVICE',
 140             nargs='?',
 141             help='Path to an lv (as vg/lv), partition (as /dev/sda1) or device (as /dev/sda)'
 142         )
 143         parser.add_argument(
 144             '--destroy',
 145             action='store_true',
 146             default=False,
 147             help='Destroy all volume groups and logical volumes if you are zapping a raw device or partition',
 148         )
 149         if len(self.argv) == 0:
 150             print(sub_command_help)
 151             return
 152         args = parser.parse_args(self.argv)
 153         self.zap(args)