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Diffstat (limited to 'qemu-doc.texi')
| -rw-r--r-- | qemu-doc.texi | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/qemu-doc.texi b/qemu-doc.texi index f2c56ce0e..77170d3ad 100644 --- a/qemu-doc.texi +++ b/qemu-doc.texi @@ -289,6 +289,12 @@ The host page can be avoided entirely with @option{cache=none}. This will attempt to do disk IO directly to the guests memory. QEMU may still perform an internal copy of the data. +Some block drivers perform badly with @option{cache=writethrough}, most notably, +qcow2. If performance is more important than correctness, +@option{cache=writeback} should be used with qcow2. By default, if no explicit +caching is specified for a qcow2 disk image, @option{cache=writeback} will be +used. For all other disk types, @option{cache=writethrough} is the default. + Instead of @option{-cdrom} you can use: @example qemu -drive file=file,index=2,media=cdrom |