LVMPOLLD

Section: Maintenance Commands (8)
Updated: LVM TOOLS 2.03.11(2) (2021-01-08)
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NAME

lvmpolld --- LVM poll daemon

SYNOPSIS

lvmpolld [-l|--log {all|wire|debug}] [-p|--pidfile pidfile_path] [-s|--socket socket_path] [-B|--binary lvm_binary_path] [-t|--timeout timeout_value] [-f|--foreground] [-h|--help] [-V|--version]

lvmpolld [--dump]

DESCRIPTION

lvmpolld is polling daemon for LVM. The daemon receives requests for polling of already initialised operations originating in LVM2 command line tool. The requests for polling originate in the lvconvert, pvmove, lvchange or vgchange LVM2 commands.

The purpose of lvmpolld is to reduce the number of spawned background processes per otherwise unique polling operation. There should be only one. It also eliminates the possibility of unsolicited termination of background process by external factors.

lvmpolld is used by LVM only if it is enabled in lvm.conf(5) by specifying the global/use_lvmpolld setting. If this is not defined in the LVM configuration explicitly then default setting is used instead (see the output of lvmconfig --type default global/use_lvmpolld command).

OPTIONS

To run the daemon in a test environment both the pidfile_path and the socket_path should be changed from the defaults.

-f, --foreground: Don't fork, but run in the foreground.
-h, --help: Show help information.
-l, --log {all|wire|debug}: Select the type of log messages to generate. Messages are logged by syslog. Additionally, when -f is given they are also sent to standard error. There are two classes of messages: wire and debug. Selecting 'all' supplies both and is equivalent to a comma-separated list -l wire,debug.
-p, --pidfile pidfile_path: Path to the pidfile. This overrides both the built-in default (/run/lvmpolld.pid) and the environment variable LVM_LVMPOLLD_PIDFILE. This file is used to prevent more than one instance of the daemon running simultaneously.
-s, --socket socket_path: Path to the socket file. This overrides both the built-in default (/run/lvm/lvmpolld.socket) and the environment variable LVM_LVMPOLLD_SOCKET.
-t, --timeout timeout_value: The daemon may shutdown after being idle for the given time (in seconds). When the option is omitted or the value given is zero the daemon never shutdowns on idle.
-B, --binary lvm_binary_path: Optional path to alternative LVM binary (default: /usr/lvm). Use for testing purposes only.
-V, --version: Display the version of lvmpolld daemon.
--dump: Contact the running lvmpolld daemon to obtain the complete state and print it out in a raw format.

ENVIRONMENT VARIABLES

LVM_LVMPOLLD_PIDFILE: Path for the pid file.
LVM_LVMPOLLD_SOCKET: Path for the socket file.