Without O_DIRECT we weren't getting IO errors propagated from the
sendfile(2) call (not even on close). This was causing us not to notice
when copying VDIs to full thinly-provisioned SRs.
Note that the O_DIRECT open is part of the Vhd_format library and
is controlled by the 'use_unbuffered' global variable of
Vhd_format_lwt.File. See xapi-project/ocaml-vhd for the details.
Without O_DIRECT we weren't getting IO errors propagated from the sendfile(2) call (not even on close). This was causing us not to notice when copying VDIs to full thinly-provisioned SRs.
Note that the O_DIRECT open is part of the Vhd_format library and is controlled by the 'use_unbuffered' global variable of Vhd_format_lwt.File. See xapi-project/ocaml-vhd for the details.
Signed-off-by: Jon Ludlam jonathan.ludlam@citrix.com