nginx makes mysqld die all the time

[M. Fioretti]

Greetings,

I just migrated to nginx + php-fpm from apache a few websites, on a 
centos 6.6 virtual server. The sites are up but... now mysqld (MariaDB, 
actually) dies every 10/20 **minutes** with status:

mysqld dead but subsys locked

or

mysqld dead but pid file exists

for reasons not really relevant here I cannot post nginx conf
right away. I **will** do that in a few hours, when I'm back
at my desk. Since the crashes are so frequent, however, any
help to save time is very welcome. Even if it's just request
of other specific info, besides the nginx conf files.

TIA,
Marco