Implement sync option

[nbd.git] / nbd-server.5.in

diff --git a/nbd-server.5.in b/nbd-server.5.in
index ddcede2..5d461ad 100644 (file)
--- a/nbd-server.5.in
+++ b/nbd-server.5.in
@@ -3,7 +3,7 @@
 .\" <http://shell.ipoline.com/~elmert/comp/docbook2X/> 
 .\" Please send any bug reports, improvements, comments, patches, 
 .\" etc. to Steve Cheng <steve@ggi-project.org>.
-.TH "NBD-SERVER" "5" "03 January 2009" "" ""
+.TH "NBD-SERVER" "5" "17 July 2009" "" ""
 
 .SH NAME
 /etc/nbd-server/config \- configuration file for nbd-server
@@ -212,6 +212,20 @@ is found in a configuration file and
 then \fBnbd-server\fR will exit with an error
 message.
 .TP
+\fBsync\fR
+Optional; boolean.
+
+When this option is enabled,
+\fBnbd-server\fR will call an fsync() after every
+write to the backend storage. Calling fsync() increases
+reliability in case of an unclean shutdown of nbd-server; but,
+depending on the file system used on the nbd-server side, may
+degrade performance. The use of this option isn't always
+necessary; e.g., on ext3 filesystems, it is recommended that
+it is \fBnot\fR enabled, since it seriously
+reduces performance on ext3 filesystems while not
+importantly impacting performance.
+.TP
 \fBsparse_cow\fR
 Optional; boolean.