usr/src/libexec/lfs_cleanerd/lfs_cleanerd.8

.\" Copyright (c) 1993
.\"     The Regents of the University of California.  All rights reserved.
.\"
.\" %sccs.include.redist.roff%
.\"
.\"     @(#)lfs_cleanerd.8      8.2 (Berkeley) %G%
.\"
.Dd ""
.Dt LFS_CLEANERD 8
.Os BSD 4.4
.Sh NAME
.Nm lfs_cleanerd
.Nd garbage collect a log-structured file system
.Sh SYNOPSIS
.Nm lfs_cleanerd
.Op Fl ds
.Pa node
.Sh DESCRIPTION
The
.Nm lfs_cleanerd
command starts a daemon process which garbage-collects
the log-structured file system residing at the point named by
.Ar node
in the global file system namespace.
This command is normally executed by
.Xr mount_lfs 8
when the log-structured file system is mounted.
The daemon will exit within a few minutes
of when the file system it was cleaning is unmounted.
.Pp
Garbage collection on a log-structured file system is done by scanning
the file system's segments for active, i.e. referenced, data and copying
it to new segments.
When all of the active data in a given segment has been copied to a new
segment that segment can be marked as empty, thus reclaiming the space
taken by the inactive data which was in it.
.Pp
The following options are available:
.Bl -tag -width indent
.It Fl d
Run in debug mode.
Do not become a daemon process, and print debugging information.
.It Fl s
When cleaning the file system, read data in small chunks.
.El
.Sh SEE ALSO
.Xr mount_lfs 8
.Sh HISTORY
The
.Nm lfs_cleanerd
utility first appeared in 4.4BSD.