/vz partition on NFS share and you experience the following errors:
Error (vzpkg update cache) At least 27406MB more space needed on the / filesystem. Error: /usr/share/vzyum/bin/yum failed, exitcode=1
However you have plenty of disk space:
[root@myhost]# df Filesystem 1K-blocks Used Available Use% Mounted on 10.10.10.50:/mnt/vz-99 1032123392 7949312 971745280 1% /vz
The reason of the issue is
subtree_check option for nfs mount point.
There should not be securtiy checks options on file access like root squashing or subtree permissions and so on. Cancel this option and try your task once again.