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Diffstat (limited to 'docs/qcow2-cache.txt')
| -rw-r--r-- | docs/qcow2-cache.txt | 15 |
1 files changed, 10 insertions, 5 deletions
diff --git a/docs/qcow2-cache.txt b/docs/qcow2-cache.txt index 7e28b41bd3..750447ea4f 100644 --- a/docs/qcow2-cache.txt +++ b/docs/qcow2-cache.txt @@ -125,8 +125,12 @@ There are a few things that need to be taken into account: - Both caches must have a size that is a multiple of the cluster size (or the cache entry size: see "Using smaller cache sizes" below). - - The default L2 cache size is 8 clusters or 1MB (whichever is more), - and the minimum is 2 clusters (or 2 cache entries, see below). + - The maximum L2 cache size is 1 MB by default (enough for full coverage + of 8 GB images, with the default cluster size). This value can be + modified using the "l2-cache-size" option. QEMU will not use more memory + than needed to hold all of the image's L2 tables, regardless of this max. + value. The minimal L2 cache size is 2 clusters (or 2 cache entries, see + below). - The default (and minimum) refcount cache size is 4 clusters. @@ -184,9 +188,10 @@ Some things to take into account: always uses the cluster size as the entry size. - If the L2 cache is big enough to hold all of the image's L2 tables - (as explained in the "Choosing the right cache sizes" section - earlier in this document) then none of this is necessary and you - can omit the "l2-cache-entry-size" parameter altogether. + (as explained in the "Choosing the right cache sizes" and "How to + configure the cache sizes" sections in this document) then none of + this is necessary and you can omit the "l2-cache-entry-size" + parameter altogether. Reducing the memory usage |