DragonFly kernel List (threaded) for 2004-04
Re: boot-time nfs mount issues should be fixed now
On Apr 13, 2004, at 6:03 PM, Matthew Dillon wrote:
The symptoms are NFS mount failures reported on the console, but
Thanks, thats been a pain for a very long time.
NFS mount working just fine when executed manually after booting as
It turns out that the DNS resolver coupled with the use of
names in /etc/fstab was to blame for this. e.g. leaf has this:
crater:/usr/src /usr/src nfs ro,bg 0 0
apollo:/FreeBSD /FreeBSD nfs ro,bg 0 0
And sometimes /FreeBSD would not mount during booting. It turns
that the network is sometimes not fully operational when the RCNG
script gets to the NFS mounts and this causes the DNS resolver to
Normally one would expect the resolver to retry a few times and
a successful lookup. However, when a shortform name like 'crater'
used the resolver winds up trying two hostnames
and 'crater.'. If the first lookup times out, but the second one
not, the resolver returns the 'definitive' host-not-found error
the second lookup when it really should return a try-again error
the first lookup. The result is that the NFS mount fails because
thinks that it was given definitely a non-existant hostname.
This problem can also cause weird failures to occur when the
is sporatic or the name servers you are using get overloaded.
In anycase, I just committed a fix to the resolver (which hopefully
won't break anything else).