Commit Graph

5 Commits

Author SHA1 Message Date
Alberto Garcia
603790ef3a docs: Document the new default sizes of the qcow2 caches
We have just reduced the refcount cache size to the minimum unless
the user explicitly requests a larger one, so we have to update the
documentation to reflect this change.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-id: c5f0bde23558dd9d33b21fffc76ac9953cc19c56.1523968389.git.berto@igalia.com
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2018-05-15 16:15:21 +02:00
Alberto Garcia
be820971ff docs: document how to use the l2-cache-entry-size parameter
This patch updates docs/qcow2-cache.txt explaining how to use the new
l2-cache-entry-size parameter.

Here's a more detailed technical description of this feature:

   https://lists.gnu.org/archive/html/qemu-block/2017-09/msg00635.html

And here are some performance numbers:

   https://lists.gnu.org/archive/html/qemu-block/2017-12/msg00507.html

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-03-02 18:39:07 +01:00
Philippe Mathieu-Daudé
f3fdeb9c97 docs: fix broken paths to docs/interop/qcow2.txt
With the move of some docs to docs/interop on d59157ea05,
a reference path was not updated.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2017-07-31 13:12:35 +03:00
Alberto Garcia
8f57758311 docs: Specify that cache-clean-interval is only supported in Linux
Make it clear that having Linux is a hard requirement for this
feature.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-11-25 13:51:31 +01:00
Alberto Garcia
7f65ce834a docs: document how to configure the qcow2 L2/refcount caches
QEMU has options to configure the size of the L2 and refcount
caches for the qcow2 format. However, choosing the right sizes for
a particular disk image is not a straightforward operation since
the ratio between the cache size and the allocated disk space is
not obvious and depends on the size of the cluster and the refcount
entries.

This document attempts to give an overview of both caches and how to
configure their sizes.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 55de928e139b1ba3f3d40fe9c6c88f30b1f36410.1438690126.git.berto@igalia.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2015-09-04 21:00:32 +02:00