One of the ways that Solaris does not make me happy is that they do
not seem to have changed various system defaults since, oh, 1996, when
machines were much smaller than they are now. As a result, we have
accumulated a set of NFS server parameters that we have had to change in
order to get decent performance and functionality.
(This set is not particularly novel, which is part of the irritation;
pretty much everyone winds up making many of these changes sooner or
later. But instead of the system shipping with sensible defaults,
you are left to discover them on your own, or not discover them and
wonder why your theoretically powerful and modern Solaris NFS server is
performing pathetically badly. Or why it is exploding.)
Unless mentioned otherwise, all of these parameters are set (or changed,
NFSD_SERVERS, from 16 to 512
The maximum number of concurrent NFS requests.
The default is too low to get decent performance under load, and has
been for years. This is one of the standard tuneables that everyone
says you should change, but beware; the usual advice on the Internet
is to set it to 1024, but on our fileservers
having that many NFS server threads locked up my test system
(running on reasonably beefy hardware).
(Apparently the NFS server threads are very high priority, and if
you have too many of them they will happily eat all of your CPU.)
LOCKD_SERVERS, from 20 to 128
LOCKD_LISTEN_BACKLOG, from 32 to 256
The maximum number of simultaneous NFS lock requests.
We saw NFS locking failures under production load that were cured
by doing this. I believe that
LOCKD_SERVERS is the important
one, but we haven't tested this.
NFS_SERVER_VERSMAX, from 4 to 3
The maximum NFS protocol version that the server will use.
We're wimps. NFS v4 is peculiar and we've never tested it, and I
have no desire to find out all the ways that Linux and Solaris
don't get along about it. So even if machines think that they're
capable of doing it, we don't want them to.
set nfssrv:nfs_portmon = 1, which is set in
Require NFS requests to come from reserved ports. In theory you might be able to change this
on a live system with
mdb -kw, but really, just schedule a reboot.
As a cautionary note on Solaris 10 x86, remember to update the boot
archive with '
bootadm update-archive' every time
/etc/system. I don't think that changing
requires updating the boot archive, but it can't hurt to run the
Necessary disclaimer: these work for us but may not work for you.
Always test your system.