sheepdog: support user-defined redundancy option
Sheepdog support two kinds of redundancy, full replication and erasure coding.
# create a fully replicated vdi with x copies
-o redundancy=x (1 <= x <= SD_MAX_COPIES)
# create a erasure coded vdi with x data strips and y parity strips
-o redundancy=x:y (x must be one of {2,4,8,16} and 1 <= y < SD_EC_MAX_STRIP)
E.g, to convert a vdi into sheepdog vdi 'test' with 8:3 erasure coding scheme
$ qemu-img convert -o redundancy=8:3 linux-0.2.img sheepdog:test
Cc: Kevin Wolf <kwolf@redhat.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Liu Yuan <namei.unix@gmail.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 3c5e9cb..d0f70c4 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -53,6 +53,7 @@
#define BLOCK_OPT_COMPAT_LEVEL "compat"
#define BLOCK_OPT_LAZY_REFCOUNTS "lazy_refcounts"
#define BLOCK_OPT_ADAPTER_TYPE "adapter_type"
+#define BLOCK_OPT_REDUNDANCY "redundancy"
typedef struct BdrvTrackedRequest {
BlockDriverState *bs;
