1 files changed, 4 insertions, 2 deletions
diff --git a/qemu-nbd.c b/qemu-nbd.c
index 65ebec5..9d895ba 100644
--- a/qemu-nbd.c
+++ b/qemu-nbd.c
@@ -135,7 +135,9 @@ static void usage(const char *name)
 "                            'snapshot.id=[ID],snapshot.name=[NAME]', or\n"
 "                            '[ID_OR_NAME]'\n"
 "  -n, --nocache             disable host cache\n"
-"      --cache=MODE          set cache mode (none, writeback, ...)\n"
+"      --cache=MODE          set cache mode used to access the disk image, the\n"
+"                            valid options are: 'none', 'writeback' (default),\n"
+"                            'writethrough', 'directsync' and 'unsafe'\n"
 "      --aio=MODE            set AIO mode (native, io_uring or threads)\n"
 "      --discard=MODE        set discard mode (ignore, unmap)\n"
 "      --detect-zeroes=MODE  set detect-zeroes mode (off, on, unmap)\n"
@@ -552,7 +554,7 @@ int main(int argc, char **argv)
     bool alloc_depth = false;
     const char *tlscredsid = NULL;
     bool imageOpts = false;
-    bool writethrough = true;
+    bool writethrough = false; /* Client will flush as needed. */
     bool fork_process = false;
     bool list = false;
     int old_stderr = -1;