qcow2: Change default cluster size to 64k

Larger cluster sizes mean less metadata. This has been discussion a few times,
let's do it now. This turns 64k clusters on by default for new images.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

diff --git a/block/qcow2.c b/block/qcow2.c
index c2be42ed3c1857fde1069937d15c707b1a59d7e5..14d8751a9f3530bfa27c82b4f9c5ce41ccf43c91 100644 (file)
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -1703,7 +1703,7 @@ static int qcow_create(const char *filename, QEMUOptionParameter *options)
     const char *backing_fmt = NULL;
     uint64_t sectors = 0;
     int flags = 0;
-    size_t cluster_size = 4096;
+    size_t cluster_size = 65536;
 
     /* Read out options */
     while (options && options->name) {