--- Begin Message ---
and use it for plugin linked clone
This also enable extended_l2=on, as it's mandatory for backing file
preallocation.
Preallocation was missing previously, so it should increase performance
for linked clone now (around x5 in randwrite 4k)
cluster_size is set to 128k, as it reduce qcow2 overhead (reduce disk,
but also memory needed to cache metadatas)
l2_extended is not enabled yet on base image, but it could help too
to reduce overhead without impacting performance
bench on 100G qcow2 file:
fio --filename=/dev/sdb --direct=1 --rw=randwrite --bs=4k --iodepth=32
--ioengine=libaio --name=test
fio --filename=/dev/sdb --direct=1 --rw=randread --bs=4k --iodepth=32
--ioengine=libaio --name=test
base image:
randwrite 4k: prealloc=metadata, l2_extended=off, cluster_size=64k: 20215
randread 4k: prealloc=metadata, l2_extended=off, cluster_size=64k: 22219
randwrite 4k: prealloc=metadata, l2_extended=on, cluster_size=64k: 20217
randread 4k: prealloc=metadata, l2_extended=on, cluster_size=64k: 21742
randwrite 4k: prealloc=metadata, l2_extended=on, cluster_size=128k: 21599
randread 4k: prealloc=metadata, l2_extended=on, cluster_size=128k: 22037
clone image with backing file:
randwrite 4k: prealloc=metadata, l2_extended=off, cluster_size=64k: 3912
randread 4k: prealloc=metadata, l2_extended=off, cluster_size=64k: 21476
randwrite 4k: prealloc=metadata, l2_extended=on, cluster_size=64k: 20563
randread 4k: prealloc=metadata, l2_extended=on, cluster_size=64k: 22265
randwrite 4k: prealloc=metadata, l2_extended=on, cluster_size=128k: 18016
randread 4k: prealloc=metadata, l2_extended=on, cluster_size=128k: 21611
Signed-off-by: Alexandre Derumier <alexandre.derum...@groupe-cyllene.com>
---
src/PVE/Storage/Common.pm | 17 +++++++++++++----
src/PVE/Storage/Plugin.pm | 5 +----
2 files changed, 14 insertions(+), 8 deletions(-)
diff --git a/src/PVE/Storage/Common.pm b/src/PVE/Storage/Common.pm
index 0770d70..01a995a 100644
--- a/src/PVE/Storage/Common.pm
+++ b/src/PVE/Storage/Common.pm
@@ -148,14 +148,23 @@ sub preallocation_cmd_option {
}
sub qemu_img_create {
- my ($scfg, $fmt, $size, $path) = @_;
+ my ($scfg, $fmt, $size, $path, $backing_path) = @_;
+
+ die "size can't be specified if backing file is used" if $size &&
$backing_path;
my $cmd = ['/usr/bin/qemu-img', 'create'];
- my $prealloc_opt = preallocation_cmd_option($scfg, $fmt);
- push @$cmd, '-o', $prealloc_opt if defined($prealloc_opt);
+ my $options = [];
+
+ if($backing_path) {
+ push @$cmd, '-b', $backing_path, '-F', 'qcow2';
+ push @$options, 'extended_l2=on','cluster_size=128k';
+ };
- push @$cmd, '-f', $fmt, $path, "${size}K";
+ push @$options, preallocation_cmd_option($scfg, $fmt);
+ push @$cmd, '-o', join(',', @$options) if @$options > 0;
+ push @$cmd, '-f', $fmt, $path;
+ push @$cmd, "${size}K" if $size;
run_command($cmd, errmsg => "unable to create image");
}
diff --git a/src/PVE/Storage/Plugin.pm b/src/PVE/Storage/Plugin.pm
index 7030e4e..a3856ca 100644
--- a/src/PVE/Storage/Plugin.pm
+++ b/src/PVE/Storage/Plugin.pm
@@ -847,10 +847,7 @@ sub clone_image {
eval {
local $CWD = $imagedir;
- my $cmd = ['/usr/bin/qemu-img', 'create', '-b',
"../$basevmid/$basename",
- '-F', $format, '-f', 'qcow2', $path];
-
- run_command($cmd);
+ PVE::Storage::Common::qemu_img_create($scfg, $format, undef, $path,
"../$basevmid/$basename");
};
my $err = $@;
--
2.39.5
--- End Message ---
