Signed-off-by: Leonid Bloch <lbl...@janustech.com> --- docs/qcow2-cache.txt | 3 +++ qemu-options.hx | 9 ++++++--- 2 files changed, 9 insertions(+), 3 deletions(-)
diff --git a/docs/qcow2-cache.txt b/docs/qcow2-cache.txt index 8a09a5cc5f..5bf2a8ad29 100644 --- a/docs/qcow2-cache.txt +++ b/docs/qcow2-cache.txt @@ -130,6 +130,9 @@ 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. + - At most two of "l2-cache-size", "refcount-cache-size", and "cache-size" + can be set simultaneously. + 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 diff --git a/qemu-options.hx b/qemu-options.hx index b1bf0f485f..f6804758d3 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -752,15 +752,18 @@ image file) @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 defined - 1048576 bytes or 8 clusters, whichever +is larger; otherwise, as large as possible or needed 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. -- 2.17.1