[Spacewalk-list] Invalid cross-device link error

[Pierre Casenove]

Hello,
I have spacewalk 1.6 on postgresql and I have the following error log
when trying to reposync packages dowloaded by mrepo:
57/57 : busybox-1.2.0-10.el5_7.1-1.x86_64
(50, 'Package upload failed: [Errno 18] Invalid cross-device link',
'Invalid information uploaded to the server')

Could you please tell me waht is the meaning of such error?

Thanks in advance,

Pierre