Ok for Views to use same Zone information?

[Chris Thompson]

On Sep 8 2007, Barry Margolin wrote:

>In article <fbqnhi$1b71$1 at sf1.isc.org>,
> "Paine, Thomas Asa" <PAINETA at uwec.edu> wrote:
>
>> For example if View 1 and View 2 differ in options, but don't really differ 
>> in zone information is it ok to do this...
>> 
>> view "view1" {
>>         <specific view1 options and/or zones>
>> 
>>         zone "foobar.com" {
>>                 type slave;
>>                 file "db.foobar.com";
>>                 masters { somelist; };
>>         };
>> };
>> 
>> view "view2" {
>>         <specific view2 options and/or zones>
>> 
>>         zone "foobar.com" {
>>                 type slave;
>>                 file "db.foobar.com";
>>                 masters { somelist; };
>>         };
>> };
>> 
>> Will bind use the same instance/cache/backups regarding file "db.foobar.com" 
>> or do the two zone declarations have to specify unique files?
>
>It's OK to do this for master zones,

Unless you are using dynamic update.

<                                     but not for slave zones.  The 
>problem is that both views might try to transfer the zone concurrently, 
>and both try to write to the same file.

Similarlly, even without views, it's a very bad idea to pun the files
for slave zones that are "known" to be identical on the  master from which
they are being fetched.

Disk space is cheap - don't take short cuts. (BIND could help by at least
issuing a warning if more than one "file" value resolves to the same place.)

-- 
Chris Thompson
Email: cet1 at cam.ac.uk