I'd restarted among controlled server coupled with strange situation: /tmp becomes filled with submitted files. move_submitted_file works not surprisingly, PHP and Apache error logs are empty (there is some Alerts that doesn't connect with this issue).

I attempted to found the main reason, and so i change upload_tmp_dir to /tmp/uploads in php.ini and restart Apache. Next "lsof /tmp" results strange log:

php 29007 webuser 17r REG 0,22 389161 52039971 /tmp/webuserjReqqp
php 29007 webuser 17r REG 0,22 311739 52042859 /tmp/webuser1SGrJK
httpd 1146 webuser mem REG 0,22 1169082 52053441 /tmp/uploads/phpJAiz0F
httpd 1146 webuser 15u REG 0,22 1169082 52053441 /tmp/uploads/phpJAiz0F
php 29007 webuser 17r REG 0,22 316849 52056728 /tmp/webuseriCSUB4
php 29007 webuser 17r REG 0,22 324447 52056931 /tmp/webuserJIWgw2
php 29007 webuser 17r REG 0,22 1591592 52059078 /tmp/webuserIJm88x

So PHP works together with /tmp/uploads not surprisingly, why Apache produces files in /tmp?