diff --git a/nixos/roles/kvm.nix b/nixos/roles/kvm.nix
index 5e64414e2..015e0b699 100644
--- a/nixos/roles/kvm.nix
+++ b/nixos/roles/kvm.nix
@@ -17,8 +17,9 @@ in
       supportsContainers = fclib.mkDisableDevhostSupport;
       mkfsXfsFlags = lib.mkOption {
         type = with lib.types; nullOr str;
-        # XXX: reflink=0 can be removed when 15.09 is out. See #PL-130977
+        # XXX: reflink=0 can be removed when 15.09 is gone. See PL-130977
         # XXX: set reflink=0 to make file systems compatible with NixOS 15.09
+        # XXX: set bigtime=1 once 15.09 and 20.09 are gone. See PL-130365.
         default = "-q -f -K -m crc=1,finobt=1,reflink=0 -d su=4m,sw=1";
       };
       migrationBandwidth = lib.mkOption {
diff --git a/pkgs/fc/default.nix b/pkgs/fc/default.nix
index d1408c824..8c7d6d8d7 100644
--- a/pkgs/fc/default.nix
+++ b/pkgs/fc/default.nix
@@ -34,12 +34,12 @@ rec {
   megacli = callPackage ./megacli { };
   multiping = callPackage ./multiping.nix {};
   qemu-nautilus = callPackage ./qemu rec {
-    version = "1.4.3";
+    version = "1.4.4";
     src = pkgs.fetchFromGitHub {
       owner = "flyingcircusio";
       repo = "fc.qemu";
       rev = version;
-      hash = "sha256-1kMdHXjsxxIW0bEV6PfDeagdLVxZP87kPKm0Z4ZtXJA=";
+      hash = "sha256-JyKToKWrkA1GT8GtayDyXHZvp2/UzrFFNednAavax2w=";
     };
     qemu_ceph = pkgs.qemu-ceph-nautilus;
     ceph_client = pkgs.ceph-nautilus.ceph-client;
diff --git a/pkgs/restore-single-files/restore-single-files.sh b/pkgs/restore-single-files/restore-single-files.sh
index d08a30041..413a78b3d 100644
--- a/pkgs/restore-single-files/restore-single-files.sh
+++ b/pkgs/restore-single-files/restore-single-files.sh
@@ -56,6 +56,13 @@ while [ ! -e $LOOPPART ]; do
 	sleep 0.2
 done
 
+info "Pre-mounting image to flush log"
+mount -oloop ${LOOPPART} $LOOPMNT
+umount $LOOPMNT
+
+info "Regenerating UUID to avoid collisions"
+xfs_admin -U generate ${LOOPPART}
+
 info "Mounting image"
 mount -oloop ${LOOPPART} $LOOPMNT
 
diff --git a/tests/kvm_host_ceph-nautilus.nix b/tests/kvm_host_ceph-nautilus.nix
index dd327febb..43fb9ea5d 100644
--- a/tests/kvm_host_ceph-nautilus.nix
+++ b/tests/kvm_host_ceph-nautilus.nix
@@ -421,6 +421,8 @@ in
 
     with subtest("Initialize first mon"):
       host1.succeed('fc-ceph osd prepare-journal /dev/vdb')
+      host1.execute('systemctl stop fc-ceph-mon')
+      host1.execute('systemctl reset-failed fc-ceph-mon')
       host1.execute('fc-ceph mon create --no-encrypt --size 500m --bootstrap-cluster > /dev/kmsg 2>&1')
       host1.sleep(5)
       host1.succeed('ceph -s > /dev/kmsg 2>&1')
@@ -452,6 +454,11 @@ in
       host1.succeed("rbd pool init rbd.hdd")
 
       host1.succeed("rbd create --size 100 rbd.hdd/fc-21.05-dev")
+      host1.succeed("rbd map rbd.hdd/fc-21.05-dev")
+      host1.succeed("sgdisk /dev/rbd0 -o -a 2048 -n 1:8192:0 -c 1:ROOT -t 1:8300")
+      host1.succeed("partprobe")
+      host1.succeed("mkfs.xfs /dev/rbd0p1")
+      host1.succeed("rbd unmap /dev/rbd0")
       host1.succeed("rbd snap create rbd.hdd/fc-21.05-dev@v1")
       host1.succeed("rbd snap protect rbd.hdd/fc-21.05-dev@v1")