2019-04-17 19:33:58,835+0800 ERROR (vm/baaabf11) [virt.vm] (vmId='baaabf11-172d-4fac-9862-86ff05feb085') The vm start process failed (vm:937)
 378 Traceback (most recent call last):
 379   File "/usr/lib/python2.7/site-packages/vdsm/virt/vm.py", line 866, in _startUnderlyingVm
 380     self._run()
 381   File "/usr/lib/python2.7/site-packages/vdsm/virt/vm.py", line 2819, in _run
 382     self._connection.restore(fname)
 383   File "/usr/lib/python2.7/site-packages/vdsm/common/libvirtconnection.py", line 131, in wrapper
 384     ret = f(*args, **kwargs)
 385   File "/usr/lib/python2.7/site-packages/vdsm/common/function.py", line 94, in wrapper
 386     return func(inst, *args, **kwargs)
 387   File "/usr/lib64/python2.7/site-packages/libvirt.py", line 4513, in restore
 388     if ret == -1: raise libvirtError ('virDomainRestore() failed', conn=self)
 389 libvirtError: internal error: Child process (gzip -dc) unexpected exit status 2:
 390 gzip: stdin: decompression OK, trailing garbage ignored
 391 
 392 2019-04-17 19:33:58,835+0800 INFO  (vm/baaabf11) [virt.vm] (vmId='baaabf11-172d-4fac-9862-86ff05feb085') Changed state to Down: internal error: Child process (gzip -dc) unexpected exit status 2:
 393 gzip: stdin: decompression OK, trailing garbage ignored
 394  (code=1) (vm:1675)
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    After i read the Bug 1503468 (https://bugzilla.redhat.com/show_bug.cgi?id=1503468#c40),  I know the reason why that happened.
But how should I avoid this exception?  The only method i know and tested is to change gzip to lzop in /etc/libvirt/qemu.conf.  But this is 
not the way to solve the problem.