If you run the updater tool from the Plesk CP it returns the error:
Warning: Error: Can't create directory //psa/.
However it works fine from the command line.
When you run updater tool from the Plesk CP, it gets 'root' privileges by means of 'wrapper' utility that has 'SUID' bit set. If updater gets the permission error, most probably it was not able to get 'root' privileges due to 'SUID' bit absence.
Make sure that $PRODUCT_ROOT_D/admin/sbin/wrapper binary has right permissions as listed below:
# ls -la /usr/local/psa/admin/sbin/wrapper ---s--x--- 1 root psaadm 13632 Jun 13 2006 /usr/local/psa/admin/sbin/wrapper
# chmod 4110 /usr/local/psa/admin/sbin/wrapper
Also make sure that /usr/local/psa/admin/bin/autoinstaller is a symlink to /usr/local/psa/admin/sbin/wrapper :
# ls -la /usr/local/psa/admin/bin/autoinstaller
lrwxr-xr-x 1 root psaadm 15 Jul 16 14:59 /usr/local/psa/admin/bin/autoinstaller -> ../sbin/wrapper