nsupdate

[Cricket Liu]

Michel Marcon <NOSPAM.michel.marcon at vnumail.com> wrote in message
news:<37c97e19.6784873 at news.vnumail.com>...
> On 27 Aug 1999 15:04:40 -0700, "Pandit, Tushar"
> <tpandit at imps0014.us.dg.com> wrote:
> >I am testing the 'nsupdate' feature in bind 8.2. When I add a record to a
zone  file  x.hosts, nsupdate
> >creates two files x.hosts.ixfr and x.hosts.log, which contain only the
updated record. The original zone
> >file x.hosts does not contain the update. Is this correct ? I thought the
original file would have the updated
> >record.
> AFAIK this behavior is correct. What's more, after a certain time,
> this two files will be automatically merged with the normal files.
> Or you can stop than start (or restart?) your DNS server with ndc with
> the same effect.
>
> Cricket, correct me if I'm wrong, pls.

That's basically right.  The .log file is BIND's way of "journaling" dynamic
updates to the zone.  Each time BIND receives a dynamic update, it writes a
record of the update to the .log file.  Roughly each hour, it should rewrite
the whole zone data file from its in-memory copy of the zone and delete the
.log file.  This is a Good Thing because BIND doesn't have to rewrite a
potentially very large zone data file each time it gets a dynamic update,
yet it commits a record of the dynamic update to stable storage so it won't
be lost if BIND crashes.  When BIND starts, of course, it aggregates any
.log file into the current zone.

The .ixfr file is yet another record of changes to the zone, but in this
case for incremental zone transfers.  BIND master name servers keep a record
of the changes between one serial number and the next, so that when a slave
requests the delta between serial 1999083000 and 1999083002, it can provide
it.

cricket

Acme Byte & Wire
cricket at acmebw.com
www.acmebw.com

Attend our next DNS and BIND class!  See
www.acmebw.com/training.htm for the
schedule and to register for upcoming
classes.