[libvirt] [PATCH] qemu: work around dash 0.5.5 bug in managed save

[Justin Clift]

On 10/23/2010 10:29 AM, Eric Blake wrote:
> * configure.ac (VIR_WRAPPER_SHELL): Define to a replacement shell,
> if /bin/sh is broken on <> redirection.
> * src/qemu/qemu_monitor.h (VIR_WRAPPER_SHELL_PREFIX)
> (VIR_WRAPPER_SHELL_SUFFIX): New macros.
> * src/qemu/qemu_monitor_text.c (qemuMonitorTextMigrateToFile): Use
> them.
> * src/qemu/qemu_monitor_json.c (qemuMonitorJSONMigrateToFile):
> Likewise.
> ---
> 
> Took longer than I thought, but this should do the trick with no
> overhead on decent systems, and while still avoiding buggy dash ==
> /bin/sh with something that works elsewhere.
> 
> This passes for me on Fedora, where /bin/sh is bash; testing on
> Ubuntu or other debian-based system where /bin/sh is dash 0.5.5
> would be appreciated.

No obvious errors crop up when testing this on Ubuntu 10.04:

  virsh # managedsave 1
  Domain 1 state saved by libvirt

  virsh #

As a usability thing though, there doesn't seem to be a matching
"managedrestore" command in virsh, and the "help managedsave"
command is bit light on "how do we restart a saved domain?":

  # help managedsave
    NAME
      managedsave - managed save of a domain state

    SYNOPSIS
      managedsave <domain>

    DESCRIPTION
      Save and stop a running domain, so libvirt can restart it from
      the same state

    OPTIONS
      [--domain] <string>  domain name, id or uuid

Are we supposed to restart it using "start" or something?  (we need
to mention this, which I can follow up with a patch)