Comment # 3 on bug 1230345 from Ruediger Oertel

without multipath the "-V" ends with:
zIPL environment block content:
Preparing boot device for LD-IPL: sdb.
Detected plain SCSI partition.
Writing SCSI master boot record.
Syncing disks...
Done.

and the strace ends with:
3467985 write(1, "    initial ramdisk.: 0x00a20000"..., 44) = 44
3467985 write(1, "    environment blk.: 0x00a18000"..., 44) = 44
3467985 lseek(3, 0, SEEK_CUR)           = 49664
3467985 write(3,
"zIPL\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 512) = 512
3467985 fstatfs64(3, 88, {f_type=EXT2_SUPER_MAGIC, f_bsize=4096,
f_blocks=1030072, f_bfree=943156, f_bavail=890728, f_files=262144,
f_ffree=262115, f_fsid={val=[0xb175a6e9, 0x95ddf447]}, f_namelen=255,
f_frsize=4096, f_flags=ST_VALID|ST_RELATIME}) = 0
3467985 ioctl(3, FS_IOC_FIEMAP, {fm_start=49664, fm_length=4096,
fm_flags=FIEMAP_FLAG_SYNC, fm_extent_count=1} => {fm_flags=FIEMAP_FLAG_SYNC,
fm_mapped_extents=1, ...}) = 0
3467985 write(1, "zIPL environment block content:\n", 32) = 32
3467985 lseek(3, 0, SEEK_CUR)           = 50176
3467985 write(3,
"zIPL\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0x@a\2\0\0\0\0\0\0\0"..., 512) = 512
3467985 fstatfs64(3, 88, {f_type=EXT2_SUPER_MAGIC, f_bsize=4096,
f_blocks=1030072, f_bfree=943156, f_bavail=890728, f_files=262144,
f_ffree=262115, f_fsid={val=[0xb175a6e9, 0x95ddf447]}, f_namelen=255,
f_frsize=4096, f_flags=ST_VALID|ST_RELATIME}) = 0
3467985 ioctl(3, FS_IOC_FIEMAP, {fm_start=50176, fm_length=4096,
fm_flags=FIEMAP_FLAG_SYNC, fm_extent_count=1} => {fm_flags=FIEMAP_FLAG_SYNC,
fm_mapped_extents=1, ...}) = 0
3467985 write(1, "Preparing boot device for LD-IPL"..., 39) = 39
3467985 openat(AT_FDCWD, "/dev/zipl0000", O_RDWR) = 4
3467985 ioctl(4, BLKFLSBUF)             = 0
3467985 lseek(4, 0, SEEK_SET)           = 0
3467985 read(4,
"zIPL\0\0\0\1\0\0\0\0\0\0\0\0\0\0\0\0\0x`\2\2\0\0\0\0\0\0\0"..., 512) = 512
3467985 write(1, "Detected plain SCSI partition.\n", 31) = 31
3467985 write(1, "Writing SCSI master boot record."..., 33) = 33
3467985 lseek(4, 0, SEEK_SET)           = 0
3467985 write(4,
"zIPL\0\0\0\1\0\0\0\0\0\0\0\0\0\0\0\0\0x@b\2\0\0\0\0\0\0\0"..., 512) = 512
3467985 fsync(4)                        = 0
3467985 close(4)                        = 0
3467985 openat(AT_FDCWD, "/etc/localtime", O_RDONLY|O_CLOEXEC) = 4
3467985 fstat(4, {st_mode=S_IFREG|0644, st_size=114, ...}) = 0
3467985 fstat(4, {st_mode=S_IFREG|0644, st_size=114, ...}) = 0
3467985 read(4,
"TZif2\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 4096) = 114
3467985 lseek(4, -60, SEEK_CUR)         = 54
3467985 read(4,
"TZif2\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 4096) = 60
3467985 close(4)                        = 0
3467985 socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0) = 4
3467985 connect(4, {sa_family=AF_UNIX, sun_path="/dev/log"}, 110) = 0
3467985 send(4, "<14>Sep 11 16:23:44 zipl: Boot l"..., 60, MSG_NOSIGNAL) = 60
3467985 rename("/boot2/zipl/bootmap_temp.PbIcra", "/boot2/zipl/bootmap") = 0
3467985 close(3)                        = 0
3467985 unlink("/dev/zipl0000")         = 0
3467985 write(1, "Syncing disks...\n", 17) = 17
3467985 sync()                          = 0
3467985 write(1, "Done.\n", 6)          = 6
3467985 exit_group(0)                   = ?
3467985 +++ exited with 0 +++