lvm2-activation-generator (8)
NAME
lvm2-activation-generator - generator for systemd units to activate LVM2 volumes on bootSYNOPSIS
/lib/systemd/system-generators/lvm2-activation-generator
DESCRIPTION
The lvm2-activation-generator is called by systemd(1) on boot to generate systemd units at runtime to activate LVM2 volumes if lvmetad(8) is disabled (global/use_lvmetad=0 lvm.conf(5) option is used). Otherwise, if lvmetad(8) is enabled, the lvm2-activation-generator exits immediately without generating any systemd units and LVM2 fully relies on event-based activation to activate the LVM2 volumes instead using the pvscan(8) (pvscan --cache -aay) call that is a part of udev(8) rules.These systemd units are generated by lvm2-activation-generator:
lvm2-activation-early.service
used for activation of LVM2 volumes that is ordered before systemd's
special cryptsetup.target to support LVM2 volumes which are not
layered on top of encrypted devices.
lvm2-activation.service
used for activation of LVM2 volumes that is ordered after systemd's
special cryptsetup.target to support LVM2 volumes which are
layered on top of encrypted devices.
lvm2-activation-net.service
used for activation of LVM2 volumes that is ordered after systemd's
special remote-fs-pre.target to support LVM2 volumes which are
layered on attached remote devices.
Note that all the underlying devices (Physical Volumes) need to be present
when the service is run. If the there are any devices presented in the system
anytime later, any LVM2 volumes on top of such devices need to be activated
directly by lvchange(8) or vgchange(8). This limitation does
not exist when using lvmetad(8) and accompanying event-based activation
since such LVM volumes are activated automatically as soon as the Volume Group
is ready (all the Physical Volumes making up the Volume Group are present
in the system).
The lvm2-activation-generator implements the Generators Specification
as referenced in systemd(1).