Signed-off-by: Wenchao Xia <xiaw...@linux.vnet.ibm.com>
---
qemu-nbd.c | 11 ++++++++++-
qemu-nbd.texi | 11 ++++++++++-
2 files changed, 20 insertions(+), 2 deletions(-)
diff --git a/qemu-nbd.c b/qemu-nbd.c
index 6588a1f..49dfc14 100644
--- a/qemu-nbd.c
+++ b/qemu-nbd.c
@@ -80,7 +80,16 @@ static void usage(const char *name)
"\n"
"Block device options:\n"
" -r, --read-only export read-only\n"
-" -s, --snapshot use snapshot file\n"
+" -s, --snapshot use FILE as an external snapshot, create a temporary\n"
+" file with backing_file=FILE, redirect the write to\n"
+" the temporary one\n"
+" -l, --load-snapshot=SNAPSHOT_ID_OR_NAME\n"
+" load an internal snapshot inside FILE and export it\n"
+" as an read-only device\n"
+" -L, --load-snapshot1=SNAPSHOT_PARAM\n"
+" load an internal snapshot inside FILE and export it\n"
+" as an read-only device, SNAPSHOT_PARAM format is\n"
+" 'snapshot.id=[ID],snapshot.name=[NAME]'\n"
" -n, --nocache disable host cache\n"
" --cache=MODE set cache mode (none, writeback, ...)\n"
#ifdef CONFIG_LINUX_AIO
diff --git a/qemu-nbd.texi b/qemu-nbd.texi
index 6055ec6..5940905 100644
--- a/qemu-nbd.texi
+++ b/qemu-nbd.texi
@@ -27,7 +27,16 @@ Export QEMU disk image using NBD protocol.
@item -P, --partition=@var{num}
only expose partition @var{num}
@item -s, --snapshot
- use snapshot file
+ use @var{filename} as an external snapshot, create a temporary
+ file with backing_file=@var{filename}, redirect the write to
+ the temporary one
+@item -l, --load-snapshot=@var{snapshot_id_or_name}
+ load an internal snapshot inside @var{filename} and export it
+ as an read-only device
+@item -L, --load-snapshot1=@var{snapshot_param}
+ load an internal snapshot inside @var{filename} and export it
+ as an read-only device, @var{snapshot_param} format is
+ 'snapshot.id=[ID],snapshot.name=[NAME]'
@item -n, --nocache
@itemx --cache=@var{cache}
set cache mode to be used with the file. See the documentation of
--
1.7.1
