system slowdown - vnode related

[The Hermit Hacker]

On Sun, 25 May 2003, Steve Watt wrote:

> In article <20030524190051.R598 at hub.org>, scrappy at hub.org wrote:
> >  What version of FreeBSD are you running?  There were several fixes put
> >in just after 4.8 was released, one of which dealt with freeing up vnodes,
> >since I was hitting similar problems on our server where we're using
> >unionfs ...
>
> If you're on stable, I suggest reading the man page for mount_union very
> carefully, especially the BUGS section.
>
> Be verrrry careful, you're in dangerous territory.
>
> (Yes, I've hurt myself on that.)

Have been using unionfs for the past 6 months or so, and, if you've
followed my threads in this group, am pushing several limits as far as the
OS is concerned in a 32bit environment (especially with regards to vnodes)
... so far, other then the very very occasional directory inode crashes,
any problem that I've had has been related to kernel structures ...

My 'heaviest server' right now is running:

neptune# df -t union | wc -l
      55

and my other servers around 30 or so ...

I'm of the belief that problems don't, and won't, get fixed unless ppl are
both using the feature, and providing bug reports for them ... so far,
thanks to the help of several FreeBSD kernel developers, there have been a
few bugs 'knocked off' and fixed in 4.x ... and, hopefully over the next
few months, I can help knock off a few more ...