Re: Block alignment of qcow2 compress driver

[Richard W.M. Jones]

I hacked nbdcopy to ignore block alignment (the error actually comes
from libnbd refusing to send the unaligned request, not from
qemu-nbd), and indeed qemu-nbd accepts the unaligned request without
complaint.

Eric - maybe having some flag for nbdcopy to ignore unaligned requests
when we know the server doesn't care (qemu-nbd) would work?

Rich.

--- a/copy/nbd-ops.c
+++ b/copy/nbd-ops.c
@@ -59,6 +59,10 @@ open_one_nbd_handle (struct rw_nbd *rwn)
     exit (EXIT_FAILURE);
   }
 
+  uint32_t sm = nbd_get_strict_mode (nbd);
+  sm &= ~LIBNBD_STRICT_ALIGN;
+  nbd_set_strict_mode (nbd, sm);
+
   nbd_set_debug (nbd, verbose);
 
   if (extents && rwn->d == READING &&


-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
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