Syslinux - Mar 2018 - failing with I/O error when loading Linux kernel

I'm trying to use syslinux 6.03 to boot a QEMU VM.
The config file is very simple:
DEFAULT foo
PROMPT 1
UI menu.c32
LABEL foo
  LINUX /boot/vmlinuz
  INITRD /boot/initrd
  APPEND root=LABEL=ROOT ro

Syslinux starts right and finds the config file (it knows what the label
foo is), but then fails to load the kernel: "Loading /boot/vmlinuz...
failed: I/O error"

I get the same error whether the VM is presenting the disk as virtio or
SATA.  I have tried MBR and GPT partitioning.  I have made sure the ext4
filesystem is made without that new troublesome 64bit extension.  I have
also tried specifying the device instead of using the label on the APPEND
line.

If I tell it to boot /boot/vmlinuks (which doesn't exist) it says
"Loading
/boot/vmlinuks... failed: No such file or directory".  This leads me to
believe that Syslinux is able to read the /boot directory but not the
kernel?  I done an MD5 sum on the kernel and the same kernel on a
different machine (which Syslinux is booting just fine) and they match so
it is not a file corruption issue.

The closest thing I have found to a related problem is:
http://www.syslinux.org/archives/2017-March/025654.html

What else should I try?
-- 
Jon Martin 
System Administrator - System Administration 1
Information Services & Technology at University of Alberta
780-492-1662  http://ualberta.ca/IST/

I found the issue and worked around it.  I had been using rsync to
populate the filesystem.  Switching to good old dump&restore made it
work.  Why, when every other variable was kept the same, the tranmission
method makes a difference I cannot say.  All the permissions, attributes,
and checksums of the kernel file matched on the sender and receiver.
I even retried some of the combinations that had previously failed and
got them working when I used dump+restore.  Something about how rsync
is putting the files on the filesystem is making Syslinux sad.

I have my solution, but if anyone wants to pick my brain about the
things I tried feel free to ask.
-- 
Jon Martin 
System Administrator - System Administration 1
Information Services & Technology at University of Alberta
780-492-1662  http://ualberta.ca/IST/

Hi,

Jon Martin wrote:
> Something about how rsync
> is putting the files on the filesystem is making Syslinux sad.
File content fragmentation comes to my mind. (Sparse file storage
is rather not a suspect, given that vmlinuz is compressed and that
FAT seems not to support this feature.)


Have a nice day :)

Thomas