Signed-off-by: Leonid Bloch <lbl...@janustech.com> --- docs/qcow2-cache.txt | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/docs/qcow2-cache.txt b/docs/qcow2-cache.txt index a0a1267482..43c0faaddb 100644 --- a/docs/qcow2-cache.txt +++ b/docs/qcow2-cache.txt @@ -110,11 +110,12 @@ How to configure the cache sizes Cache sizes can be configured using the -drive option in the command-line, or the 'blockdev-add' QMP command. -There are three options available, and all of them take bytes: +There are four options available: -"l2-cache-size": maximum size of the L2 table cache -"refcount-cache-size": maximum size of the refcount block cache -"cache-size": maximum size of both caches combined +"l2-cache-size": maximum size of the L2 table cache (bytes, K, M) +"refcount-cache-size": maximum size of the refcount block cache (bytes, K, M) +"cache-size": maximum size of both caches combined (bytes, K, M) +"l2-cache-full": make the L2 cache cover the full image (boolean) There are a few things that need to be taken into account: @@ -130,6 +131,9 @@ There are a few things that need to be taken into account: memory as possible to the L2 cache before increasing the refcount cache size. +- If "l2-cache-full" is specified, QEMU will assign enough memory + to the L2 cache to cover the entire size of the image. + Unlike L2 tables, refcount blocks are not used during normal I/O but only during allocations and internal snapshots. In most cases they are accessed sequentially (even during random guest I/O) so increasing the -- 2.14.1