@item cache-size
The maximum total size of the L2 table and refcount block caches in bytes
-(default: 1048576 bytes or 8 clusters, whichever is larger)
+(default: the sum of l2-cache-size and refcount-cache-size)
@item l2-cache-size
The maximum size of the L2 table cache in bytes
-(default: 4/5 of the total cache size)
+(default: if cache-size is not specified - 32M on Linux platforms, and 8M on
+non-Linux platforms; otherwise, as large as possible within the cache-size,
+while permitting the requested or the minimal refcount cache size)
@item refcount-cache-size
The maximum size of the refcount block cache in bytes
-(default: 1/5 of the total cache size)
+(default: 4 times the cluster size; or if cache-size is specified, the part of
+it which is not used for the L2 cache)
@item cache-clean-interval
Clean unused entries in the L2 and refcount caches. The interval is in seconds.
-The default value is 0 and it disables this feature.
+The default value is 600 on supporting platforms, and 0 on other platforms.
+Setting it to 0 disables this feature.
@item pass-discard-request
Whether discard requests to the qcow2 device should be forwarded to the data