[dns-operations] Update: Problem in Costa Rica 14 Sept.

[Stephane Bortzmeyer]

On Tue, Sep 20, 2011 at 02:54:35PM -0600,
 Luis Diego Espinoza S. <lespinoz at nic.cr> wrote 
 a message of 26 lines which said:

> One of the servers run out of disk space on Sep 14th at 7:00 am
> (13:00 UTC). Subsequently,  one of the zone files was truncated,
> resulting in a correct SOA but with less data, not an evident error.

Thanks for the report. The advices I can give (every zone generator
has to guard itself againt this sort of problems):

* always check return codes (if you use C, check the return code of
  close; or use a langauge with exceptions; in shell, use "set -e")
* check the zone file before reloading the name server: size (should
  never decrease, or only by a very small amount), amount of changes,
* add a dummy TXT at the *end* of the zone file: its absence means a
  problem,
* monitor the disk space (just in case).