lvmetad

lvmetad is useful in case you are using LVM storage backend for thick provisioning on localhost only (with no clustered setup), in this case lvmetad will provide a massive performance gain.

IMPORTANT: do not use lvmetad in case you are using shared / clustered LVM, it may be dangerous as the metadata will not be synced across the cluster.

It seems that for safety reasons to avoid people using lvmetad in clustered environments, Citrix decided to rename the binary for daemon to lvmetad_

To enable lvmetad:

• rename it in all locations from lvmetad_ to lvmetad (which lvmetad_)
• ensure that lvmetad isn't running already - if it is, it must be stopped before you enable it in configuration files
• change configuration files /etc/lvm/lvm.conf and /etc/lvm/master/lvm.conf (use_lvmetad = 1)
• enable the system service (service lvm2-lvmetad start && chkconfig lvm2-lvmetad on)