[Libguestfs] [PATCH] v2v: Use cacheextents if possible for vddk input

[Martin Kletzander]

It does not need configuring and speeds up the process of requesting extents if
the client asks for them one by one (like qemu-img).

Signed-off-by: Martin Kletzander <mkletzan at redhat.com>
---
 v2v/input_libvirt_vddk.ml | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/v2v/input_libvirt_vddk.ml b/v2v/input_libvirt_vddk.ml
index a8e4fd5ac78e..cc63f77ce825 100644
--- a/v2v/input_libvirt_vddk.ml
+++ b/v2v/input_libvirt_vddk.ml
@@ -284,6 +284,9 @@ object (self)
         add_arg "--selinux-label"; add_arg "system_u:object_r:svirt_socket_t:s0"
       );
 
+      if shell_command "nbdkit --filter cacheextents memory 1M --run true 2>/dev/null" = 0
+      then add_arg "--filter=cacheextents";
+
       (* Name of the plugin.  Everything following is a plugin parameter. *)
       add_arg "vddk";
 
-- 
2.23.0