def start_clear_holders_deps():
"""
prepare system for clear holders to be able to scan old devices
"""
# a mdadm scan has to be started in case there is a md device that needs to
# be detected. if the scan fails, it is either because there are no mdadm
# devices on the system, or because there is a mdadm device in a damaged
# state that could not be started. due to the nature of mdadm tools, it is
# difficult to know which is the case. if any errors did occur, then ignore
# them, since no action needs to be taken if there were no mdadm devices on
# the system, and in the case where there is some mdadm metadata on a disk,
# but there was not enough to start the array, the call to wipe_volume on
# all disks and partitions should be sufficient to remove the mdadm
# metadata
mdadm.mdadm_assemble(scan=True, ignore_errors=True)
# scan and activate for logical volumes
lvm.lvm_scan()
lvm.activate_volgroups()
# the bcache module needs to be present to properly detect bcache devs
# on some systems (precise without hwe kernel) it may not be possible to
# lad the bcache module bcause it is not present in the kernel. if this
# happens then there is no need to halt installation, as the bcache devices
# will never appear and will never prevent the disk from being reformatted
util.load_kernel_module('bcache')
if not zfs.zfs_supported():
LOG.warning('zfs filesystem is not supported in this environment')
def start_clear_holders_deps():
"""
prepare system for clear holders to be able to scan old devices
"""
# a mdadm scan has to be started in case there is a md device that needs to
# be detected. if the scan fails, it is either because there are no mdadm
# devices on the system, or because there is a mdadm device in a damaged
# state that could not be started. due to the nature of mdadm tools, it is
# difficult to know which is the case. if any errors did occur, then ignore
# them, since no action needs to be taken if there were no mdadm devices on
# the system, and in the case where there is some mdadm metadata on a disk,
# but there was not enough to start the array, the call to wipe_volume on
# all disks and partitions should be sufficient to remove the mdadm
# metadata
mdadm.mdadm_assemble(scan=True, ignore_errors=True)
# collect detail on any assembling arrays
for md in [
md for md in glob.glob('/dev/md*')
if not os.path.isdir(md) and not identify_partition(md)
]:
mdstat = None
if os.path.exists('/proc/mdstat'):
mdstat = util.load_file('/proc/mdstat')
LOG.debug("/proc/mdstat:\n%s", mdstat)
found = [
line for line in mdstat.splitlines()
if os.path.basename(md) in line
]
# in some cases we have a /dev/md0 device node
# but the kernel has already renamed the device /dev/md127
if len(found) == 0:
LOG.debug('Ignoring md device %s, not present in mdstat', md)
continue
# give it a second poke to encourage running
try:
LOG.debug('Activating mdadm array %s', md)
(out, err) = mdadm.mdadm_run(md)
LOG.debug('MDADM run on %s stdout:\n%s\nstderr:\n%s', md, out, err)
except util.ProcessExecutionError:
LOG.debug('Non-fatal error when starting mdadm device %s', md)
# extract details if we can
try:
(out, err) = mdadm.mdadm_query_detail(md,
export=False,
rawoutput=True)
LOG.debug('MDADM detail on %s stdout:\n%s\nstderr:\n%s', md, out,
err)
except util.ProcessExecutionError:
LOG.debug('Non-fatal error when querying mdadm detail on %s', md)
# scan and activate for logical volumes
lvm.lvm_scan()
lvm.activate_volgroups()
# the bcache module needs to be present to properly detect bcache devs
# on some systems (precise without hwe kernel) it may not be possible to
# lad the bcache module bcause it is not present in the kernel. if this
# happens then there is no need to halt installation, as the bcache devices
# will never appear and will never prevent the disk from being reformatted
util.load_kernel_module('bcache')
if not zfs.zfs_supported():
LOG.warning('zfs filesystem is not supported in this environment')