From 5c701f39f3cb7ec47c0be431648ca4a4440eeedd Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Fri, 2 Mar 2012 16:28:23 +0100 Subject: [PATCH 12/12] Documentation: Mention qcow2 full preallocation RH-Author: Kevin Wolf Message-id: <1330705703-8967-5-git-send-email-kwolf@redhat.com> Patchwork-id: 37895 O-Subject: [RHEL-6.3 qemu-kvm PATCH 4/4] Documentation: Mention qcow2 full preallocation Bugzilla: 676484 RH-Acked-by: Ademar de Souza Reis Jr. RH-Acked-by: Markus Armbruster RH-Acked-by: Luiz Capitulino Bugzilla: 676484 Upstream: n/a (full preallocation doesn't exist upstream) Signed-off-by: Kevin Wolf --- qemu-img.texi | 9 ++++++--- 1 files changed, 6 insertions(+), 3 deletions(-) Signed-off-by: Michal Novotny --- qemu-img.texi | 9 ++++++--- 1 files changed, 6 insertions(+), 3 deletions(-) diff --git a/qemu-img.texi b/qemu-img.texi index 8fce632..02ffdd0 100644 --- a/qemu-img.texi +++ b/qemu-img.texi @@ -214,9 +214,12 @@ sizes can improve the image file size whereas larger cluster sizes generally provide better performance. @item preallocation -Preallocation mode (allowed values: off, metadata). An image with preallocated -metadata is initially larger but can improve performance when the image needs -to grow. +Preallocation mode (allowed values: off, metadata, full). An image with +preallocated metadata is initially larger but can improve performance when the +image needs to grow. Full preallocation additionally writes zeros to the whole +image in order to preallocate lower layers (e.g. the file system containing the +image file) as well. Note that full preallocation writes to every byte of the +virtual disk, so it can take a long time for large images. @end table -- 1.7.7.6