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File system snapshots are no longer experimental. Forgot to chang this man page in Nov 2011.
2012-06-11 19:25:14 +04:00
.\" $NetBSD: fssconfig.8,v 1.8 2012/06/11 15:25:14 hannken Exp $ */
The file system snapshot pseudo driver. Uses a hook in spec_strategy() to save data written from a mounted file system to its block device and a hook in dounmount(). Not enabled by default in any kernel config. Approved by: Frank van der Linden <fvdl@netbsd.org>
2003-12-10 14:40:11 +03:00
.\"
.\"
.\" Copyright (c) 2003 The NetBSD Foundation, Inc.
.\" All rights reserved.
.\"
.\" This code is derived from software contributed to The NetBSD Foundation
.\" by Juergen Hannken-Illjes.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\" notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\" notice, this list of conditions and the following disclaimer in the
.\" documentation and/or other materials provided with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
.\" POSSIBILITY OF SUCH DAMAGE.
.\"
File system snapshots are no longer experimental. Forgot to chang this man page in Nov 2011.
2012-06-11 19:25:14 +04:00
.Dd June 11, 2012
The file system snapshot pseudo driver. Uses a hook in spec_strategy() to save data written from a mounted file system to its block device and a hook in dounmount(). Not enabled by default in any kernel config. Approved by: Frank van der Linden <fvdl@netbsd.org>
2003-12-10 14:40:11 +03:00
.Dt FSSCONFIG 8
.Os
.Sh NAME
.Nm fssconfig
.Nd configure file system snapshot devices
.Sh SYNOPSIS
.Nm
Add ffs internal snapshots. Written by Marshall Kirk McKusick for FreeBSD. - Not enabled by default. Needs kernel option FFS_SNAPSHOT. - Change parameters of ffs_blkfree. - Let the copy-on-write functions return an error so spec_strategy may fail if the copy-on-write fails. - Change genfs_*lock*() to use vp->v_vnlock instead of &vp->v_lock. - Add flag B_METAONLY to VOP_BALLOC to return indirect block buffer. - Add a function ffs_checkfreefile needed for snapshot creation. - Add special handling of snapshot files: Snapshots may not be opened for writing and the attributes are read-only. Use the mtime as the time this snapshot was taken. Deny mtime updates for snapshot files. - Add function transferlockers to transfer any waiting processes from one lock to another. - Add vfsop VFS_SNAPSHOT to take a snapshot and make it accessible through a vnode. - Add snapshot support to ls, fsck_ffs and dump. Welcome to 2.0F. Approved by: Jason R. Thorpe <thorpej@netbsd.org>
2004-05-25 18:54:55 +04:00
.Op Fl cxv
The file system snapshot pseudo driver. Uses a hook in spec_strategy() to save data written from a mounted file system to its block device and a hook in dounmount(). Not enabled by default in any kernel config. Approved by: Frank van der Linden <fvdl@netbsd.org>
2003-12-10 14:40:11 +03:00
.Ar device
.Ar path
.Ar backup
.Op Ar cluster Op Ar size
.Nm
Add ffs internal snapshots. Written by Marshall Kirk McKusick for FreeBSD. - Not enabled by default. Needs kernel option FFS_SNAPSHOT. - Change parameters of ffs_blkfree. - Let the copy-on-write functions return an error so spec_strategy may fail if the copy-on-write fails. - Change genfs_*lock*() to use vp->v_vnlock instead of &vp->v_lock. - Add flag B_METAONLY to VOP_BALLOC to return indirect block buffer. - Add a function ffs_checkfreefile needed for snapshot creation. - Add special handling of snapshot files: Snapshots may not be opened for writing and the attributes are read-only. Use the mtime as the time this snapshot was taken. Deny mtime updates for snapshot files. - Add function transferlockers to transfer any waiting processes from one lock to another. - Add vfsop VFS_SNAPSHOT to take a snapshot and make it accessible through a vnode. - Add snapshot support to ls, fsck_ffs and dump. Welcome to 2.0F. Approved by: Jason R. Thorpe <thorpej@netbsd.org>
2004-05-25 18:54:55 +04:00
.Fl u Op Fl v
The file system snapshot pseudo driver. Uses a hook in spec_strategy() to save data written from a mounted file system to its block device and a hook in dounmount(). Not enabled by default in any kernel config. Approved by: Frank van der Linden <fvdl@netbsd.org>
2003-12-10 14:40:11 +03:00
.Ar device
.Nm
.Fl l Op Fl v
.Op Ar device
.Sh DESCRIPTION
The
.Nm
command configures file system snapshot pseudo disk devices.
It will associate the file system snapshot disk
.Ar device
with a snapshot of
Drop trailing spaces; new sentence, new line; fix width argument to avoid confusion (indent is only magic for -offset); add a comma for easier reading.
2003-12-11 20:12:11 +03:00
.Ar path
The file system snapshot pseudo driver. Uses a hook in spec_strategy() to save data written from a mounted file system to its block device and a hook in dounmount(). Not enabled by default in any kernel config. Approved by: Frank van der Linden <fvdl@netbsd.org>
2003-12-10 14:40:11 +03:00
allowing the latter to be accessed as though it were a disk.
Note file system internal snapshots.
2005-02-01 01:08:55 +03:00
.Pp
If
.Ar backup
resides on the snapshotted file system a persistent snapshot will be created.
This snapshot is active until
.Ar backup
is unlinked.
This snapshot mode is only supported for ffs files systems.
.Pp
Otherwise data written through the
The file system snapshot pseudo driver. Uses a hook in spec_strategy() to save data written from a mounted file system to its block device and a hook in dounmount(). Not enabled by default in any kernel config. Approved by: Frank van der Linden <fvdl@netbsd.org>
2003-12-10 14:40:11 +03:00
.Ar path
will be saved in
Note file system internal snapshots.
2005-02-01 01:08:55 +03:00
.Ar backup .
The file system snapshot pseudo driver. Uses a hook in spec_strategy() to save data written from a mounted file system to its block device and a hook in dounmount(). Not enabled by default in any kernel config. Approved by: Frank van der Linden <fvdl@netbsd.org>
2003-12-10 14:40:11 +03:00
If
.Ar backup
is a regular file, it will be created with length
.Ar size .
Update the file system snapshot driver: - Document the kernel thread. - Rename some functions and variables. - Return EROFS where appropriate. - Use shifts instead of 64-bit divide. - Use a simple_lock to make it MP-safe. - Add M_CANFAIL to malloc to avoid panic on large cluster size. - Allow sparse file for backing store and use VOP_BALLOC() to allocate space. Default size of backing store is the size of the file system.
2004-01-11 22:05:26 +03:00
Default size is the size of
The file system snapshot pseudo driver. Uses a hook in spec_strategy() to save data written from a mounted file system to its block device and a hook in dounmount(). Not enabled by default in any kernel config. Approved by: Frank van der Linden <fvdl@netbsd.org>
2003-12-10 14:40:11 +03:00
.Ar path .
Data is saved to
.Ar backup
in units of
.Ar cluster
bytes.
.Pp
Options indicate an action to be performed:
Drop trailing spaces; new sentence, new line; fix width argument to avoid confusion (indent is only magic for -offset); add a comma for easier reading.
2003-12-11 20:12:11 +03:00
.Bl -tag -width 3n
The file system snapshot pseudo driver. Uses a hook in spec_strategy() to save data written from a mounted file system to its block device and a hook in dounmount(). Not enabled by default in any kernel config. Approved by: Frank van der Linden <fvdl@netbsd.org>
2003-12-10 14:40:11 +03:00
.It Fl c
Configures the device.
If successful, references to
.Ar device
will access the contents of
.Ar path
at the time the snapshot was taken.
If
.Ar backup
Drop trailing spaces; new sentence, new line; fix width argument to avoid confusion (indent is only magic for -offset); add a comma for easier reading.
2003-12-11 20:12:11 +03:00
is a directory, a temporary file will be created in this directory.
The file system snapshot pseudo driver. Uses a hook in spec_strategy() to save data written from a mounted file system to its block device and a hook in dounmount(). Not enabled by default in any kernel config. Approved by: Frank van der Linden <fvdl@netbsd.org>
2003-12-10 14:40:11 +03:00
This file will be unlinked on exit.
.It Fl l
List the snapshot devices and indicate which ones are in use.
If a specific
.Ar device
is given, then only that will be described.
.It Fl u
Unconfigures the
.Ar device .
.It Fl v
Be more verbose listing the snapshot devices.
.It Fl x
Unlink
.Ar backup
after the
.Ar device
is configured.
.El
.Pp
If no action option is given,
.Fl c
is assumed.
.Sh FILES
.Bl -tag -width /etc/disktab -compact
.It Pa /dev/rfss?
.It Pa /dev/fss?
.El
.Sh EXAMPLES
.Dl fssconfig fss0 /usr /tmp/back
.Pp
Configures the snapshot device
.Pa fss0
for a snapshot of the
.Pa /usr
Drop trailing spaces; new sentence, new line; fix width argument to avoid confusion (indent is only magic for -offset); add a comma for easier reading.
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file system.
Data written through
The file system snapshot pseudo driver. Uses a hook in spec_strategy() to save data written from a mounted file system to its block device and a hook in dounmount(). Not enabled by default in any kernel config. Approved by: Frank van der Linden <fvdl@netbsd.org>
2003-12-10 14:40:11 +03:00
.Pa /usr
will be backed up in
.Pa /tmp/back .
.Pp
.Dl fssconfig fss1 / /dev/rsd0e 8192
.Pp
Configures the snapshot device
.Pa fss1
for a snapshot of the
.Pa /
Drop trailing spaces; new sentence, new line; fix width argument to avoid confusion (indent is only magic for -offset); add a comma for easier reading.
2003-12-11 20:12:11 +03:00
file system.
Data written through
The file system snapshot pseudo driver. Uses a hook in spec_strategy() to save data written from a mounted file system to its block device and a hook in dounmount(). Not enabled by default in any kernel config. Approved by: Frank van der Linden <fvdl@netbsd.org>
2003-12-10 14:40:11 +03:00
.Pa /
will be backed up in
.Pa /dev/rsd0e .
The backup will take place in units of 8192 bytes.
.Pp
.Dl fssconfig -u fss0
.Pp
Unconfigures the
.Pa fss0
device.
.Sh SEE ALSO
.Xr opendisk 3 ,
.Xr fss 4 ,
.Xr mount 8 ,
.Xr umount 8
.Sh HISTORY
The
.Nm
command appeared in
.Nx 2.0 .