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charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable On 10.10.19 17:17, Max Reitz wrote: > Hi everyone, >=20 > (CCs just based on tags in the commit in question) >=20 > I have two bug reports which claim problems of qcow2 on XFS on ppc64le > machines since qemu 4.1.0. One of those is about bad performance > (sorry, is isn=E2=80=99t public :-/), the other about data corruption > (https://bugzilla.redhat.com/show_bug.cgi?id=3D1751934). >=20 > It looks like in both cases reverting c8bb23cbdbe3 solves the problem > (which optimized COW of unallocated areas). >=20 > I think I=E2=80=99ve looked at every angle but can=E2=80=98t find what co= uld be wrong > with it. Do any of you have any idea? :-/ I now have a reproducer with CentOS, so it=E2=80=99s actually useful outsid= e of Red Hat: $ cd $TEST_DIR (Download CentOS-8-x86_64-1905-dvd1.iso here, e.g. from http://mirror1.hs-esslingen.de/pub/Mirrors/centos/8.0.1905/isos/x86_64/Cent= OS-8-x86_64-1905-dvd1.torrent ) $ wget http://mirror1.hs-esslingen.de/pub/Mirrors/centos/8.0.1905/BaseOS/x86_64/os= /isolinux/vmlinuz $ wget http://mirror1.hs-esslingen.de/pub/Mirrors/centos/8.0.1905/BaseOS/x86_64/os= /isolinux/initrd.img $ mkdir ks $ cat > ks/ks.cfg <