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Diffstat (limited to 'docs/qcow2-cache.txt')
| -rw-r--r-- | docs/qcow2-cache.txt | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/docs/qcow2-cache.txt b/docs/qcow2-cache.txt index 750447ea4f..1fcc0658b2 100644 --- a/docs/qcow2-cache.txt +++ b/docs/qcow2-cache.txt @@ -125,12 +125,15 @@ 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 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 maximum L2 cache size is 32 MB by default on Linux platforms (enough + for full coverage of 256 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. + On non-Linux platforms the maximal value is smaller by default (8 MB) and + this difference stems from the fact that on Linux the cache can be cleared + periodically if needed, using the "cache-clean-interval" option (see below). + The minimal L2 cache size is 2 clusters (or 2 cache entries, see below). - The default (and minimum) refcount cache size is 4 clusters. |