LVM

The default volume back end uses local volumes managed by LVM.

This driver supports different transport protocols to attach volumes, currently iSCSI and iSER.

Set the following in your cinder.conf configuration file, and use the following options to configure for iSCSI transport:

volume_driver = cinder.volume.drivers.lvm.LVMVolumeDriver
target_protocol = iscsi

Use the following options to configure for the iSER transport:

volume_driver = cinder.volume.drivers.lvm.LVMVolumeDriver
target_protocol = iser

Description of LVM configuration options

Configuration option = Default value	Description
lvm_conf_file = /etc/cinder/lvm.conf	(String) LVM conf file to use for the LVM driver in Cinder; this setting is ignored if the specified file does not exist (You can also specify ‘None’ to not use a conf file even if one exists).
lvm_mirrors = 0	(Integer) If >0, create LVs with multiple mirrors. Note that this requires lvm_mirrors + 2 PVs with available space
lvm_share_target = False	(Boolean) Whether to share the same target for all LUNs or not (currently only supported by nvmet.
lvm_suppress_fd_warnings = False	(Boolean) Suppress leaked file descriptor warnings in LVM commands.
lvm_type = auto	(String(choices=[‘default’, ‘thin’, ‘auto’])) Type of LVM volumes to deploy; (default, thin, or auto). Auto defaults to thin if thin is supported.
volume_group = cinder-volumes	(String) Name for the VG that will contain exported volumes

Caution

When extending an existing volume which has a linked snapshot, the related logical volume is deactivated. This logical volume is automatically reactivated unless auto_activation_volume_list is defined in LVM configuration file lvm.conf. See the lvm.conf file for more information.

If auto activated volumes are restricted, then include the cinder volume group into this list:

auto_activation_volume_list = [ "existingVG", "cinder-volumes" ]

This note does not apply for thinly provisioned volumes because they do not need to be deactivated.