[src/trunk]: src/usr.sbin/fssconfig Describe the differences between file sys...

[hannken <hannken%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/710632878a0c
branches:  trunk
changeset: 791385:710632878a0c
user:      hannken <hannken%NetBSD.org@localhost>
date:      Fri Nov 15 09:13:57 2013 +0000

description:
Describe the differences between file system internal and external snapshots.

diffstat:

 usr.sbin/fssconfig/fssconfig.8 |  12 ++++++++++--
 1 files changed, 10 insertions(+), 2 deletions(-)

diffs (40 lines):

diff -r 51c8e6a827c5 -r 710632878a0c usr.sbin/fssconfig/fssconfig.8
--- a/usr.sbin/fssconfig/fssconfig.8    Fri Nov 15 08:47:55 2013 +0000
+++ b/usr.sbin/fssconfig/fssconfig.8    Fri Nov 15 09:13:57 2013 +0000
@@ -1,4 +1,4 @@
-.\"    $NetBSD: fssconfig.8,v 1.10 2013/03/05 23:01:06 wiz Exp $       */
+.\"    $NetBSD: fssconfig.8,v 1.11 2013/11/15 09:13:57 hannken Exp $   */
 .\"
 .\"
 .\" Copyright (c) 2003 The NetBSD Foundation, Inc.
@@ -28,7 +28,7 @@
 .\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 .\" POSSIBILITY OF SUCH DAMAGE.
 .\"
-.Dd June 11, 2012
+.Dd November 15, 2013
 .Dt FSSCONFIG 8
 .Os
 .Sh NAME
@@ -63,6 +63,10 @@
 This snapshot is active until
 .Ar backup
 is unlinked.
+Persistent snapshots save the file system as if it had been unmounted.
+Unlinked but open files get removed from the snapshot.
+The time to create a persistent snapshot increases with the size of the
+file system and decreases with the file system block size.
 This snapshot mode is only supported for FFS file systems.
 .Pp
 Otherwise data written through the
@@ -80,6 +84,10 @@
 in units of
 .Ar cluster
 bytes.
+The snapshot is an image in time of the underlying block device.
+Unlinked but open files are still present on the snapshot.
+The time to create a snapshot is independent of the size of the
+file system or the file system block size.
 .Pp
 Options indicate an action to be performed:
 .Bl -tag -width 3n