Openvz problem, it is confusing because it's an inode issue and there is enough free space.
cp: cannot create regular file `forums/memberlist.php': Disk quota exceeded
/dev/simfs 60G 20G 41G 33% /
none 2.0G 4.0K 2.0G 1% /dev
cat /proc/vz/vzquota
qid: path usage softlimit hardlimit time expire
26000: /vz/private/26000
1k-blocks 20447708 62914560 62914560 0 0
inodes 200001 200000 220000 1295689296
Solution, increase inodes:
vzctl set 26000 --diskinodes 999999999 --save
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