From f085800e245836fed27fddb3b624a29326637657 Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Wed, 13 Jun 2012 14:29:15 +0100 Subject: qemu-img: document qed format on qemu-img man page The qemu-img.1 man page is missing the qed format from its list of supported formats. Document the image creation options for qed. Suggested-by: Michael Tokarev Signed-off-by: Stefan Hajnoczi Signed-off-by: Kevin Wolf --- qemu-img.texi | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) (limited to 'qemu-img.texi') diff --git a/qemu-img.texi b/qemu-img.texi index 5a7b2bb1f2..77c6d0b6b0 100644 --- a/qemu-img.texi +++ b/qemu-img.texi @@ -237,6 +237,29 @@ to grow. @end table +@item qed +Image format with support for backing files and compact image files (when your +filesystem or transport medium does not support holes). Good performance due +to less metadata than the more featureful qcow2 format, especially with +cache=writethrough or cache=directsync. Consider using qcow2 which will soon +have a similar optimization and is most actively developed. + +Supported options: +@table @code +@item backing_file +File name of a base image (see @option{create} subcommand). +@item backing_fmt +Image file format of backing file (optional). Useful if the format cannot be +autodetected because it has no header, like some vhd/vpc files. +@item cluster_size +Changes the cluster size (must be power-of-2 between 4K and 64K). Smaller +cluster sizes can improve the image file size whereas larger cluster sizes +generally provide better performance. +@item table_size +Changes the number of clusters per L1/L2 table (must be power-of-2 between 1 +and 16). There is normally no need to change this value but this option can be +used for performance benchmarking. +@end table @item qcow Old QEMU image format. Left for compatibility. -- cgit v1.2.1