Lowering TTLs on DNS records managed by Plesk

I heartily do NOT recommend using single-server DNS solutions such as Plesk's DNS.  

That said... sometimes when it's already in use, you might want to lower all of the TTLs on the records, in batch.  ...maybe as the first step in helping migrate all of those domains over to another DNS? :-)

You can set the TTL value to any value using this command:

mysql –uadmin p`cat /etc/psa/.psa.shadow` psa –e 'update misc set val = '300' where param = 'SOA_TTL';'

You will then need to run this command to force Plesk to reread the zones files:

mysql -Ns -uadmin -p`cat /etc/psa/.psa.shadow` -D psa -e 'select name from domains' | awk '{print "/usr/local/psa/admin/sbin/dnsmng update " $1 }' | sh

The above shows a cool technique - use awk to construct commandlines that include output from a mysql select... then feed the output to shell.