unable do delete a domain

[psi123]

Hello,

when i try to delete a domain, after confirmation i get the following error:
Unable to create dnsmng object: dnsmng failed: dnsmng: Unable to search PTR records for stage.cokedjculture.org :Can't create/write to file '/tmp/#sql_a3e_0.MYI' (Errcode: 13)

0: /opt/psa/admin/plib/dns/DNSManager.php:724
DNSManager::updateDNSZone(object of type DNSZone)
1: /opt/psa/admin/plib/class.PhDomain.php:444
PhDomain->reset(integer '0', boolean true, boolean false)
2: /opt/psa/admin/plib/class.BsDomain.php:291
BsDomain->reset(integer '0')
3: /opt/psa/admin/plib/class.BsDomain.php:285
BsDomain->delete(integer '0')
4: /opt/psa/admin/plib/class.BsDomain.php:526
mdeleteDomains(array)
5: /opt/psa/admin/plib/class.Manager.php:352
Manager->removeDomains(array)
6: /opt/psa/admin/htdocs/domains/domains.php3:211

do you know which tmp directory psa process uses so one can can check?

Christian