From 46f114a53fd2948ff9b2262cb2d4de50f6b9434e Mon Sep 17 00:00:00 2001
From: Dietmar Maurer <dietmar@proxmox.com>
Date: Sat, 24 Dec 2016 10:55:31 +0100
Subject: [PATCH] storage_migrate: use bs=4k to copy images with dd

The default block size is 512 bytes, and is quite slow. We do not
want to use blocks bigger than 4k, because we want to detect empty
blocks (sparse).
---
 PVE/Storage.pm | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/PVE/Storage.pm b/PVE/Storage.pm
index a904f4e..71b699c 100755
--- a/PVE/Storage.pm
+++ b/PVE/Storage.pm
@@ -613,11 +613,11 @@ sub storage_migrate {
 
 	    eval {
 		if ($tcfg->{type} eq 'lvmthin') {
-		    run_command([["dd", "if=$src"],["/usr/bin/ssh", "root\@${target_host}",
-			      "dd", 'conv=sparse', "of=$dst"]]);
+		    run_command([["dd", "if=$src", "bs=4k"],["/usr/bin/ssh", "root\@${target_host}",
+			      "dd", 'conv=sparse', "of=$dst", "bs=4k"]]);
 		} else {
-		    run_command([["dd", "if=$src"],["/usr/bin/ssh", "root\@${target_host}",
-			      "dd", "of=$dst"]]);
+		    run_command([["dd", "if=$src", "bs=4k"],["/usr/bin/ssh", "root\@${target_host}",
+			      "dd", "of=$dst", "bs=4k"]]);
 		}
 	    };
 	    if (my $err = $@) {