On Dec 30, 2011, at 11:58 PM, <[email protected]> wrote:

> Old Synopsis: [rc.d] [patch] The mountlate RCNG boot script cannot be disabled
> New Synopsis: [rc.d] [patch] The mountlate rc.d boot script cannot be disabled
> 
> State-Changed-From-To: open->closed

Should I take this one to the forums to get a wider consensus?

Because everybody in the community I talk to agrees with me -- in the sense 
that mountlate should be abled to be disabled for those that desire-to.


> State-Changed-By: dougb
> State-Changed-When: Sat Dec 31 07:54:00 UTC 2011
> State-Changed-Why: 
> 
> 1. What you're talking about is an extreme edge case.

I completely disagree.

About 10 years ago, our company paid into the FreeBSD community 
tens-of-thousands of dollars to make certain that NFS was both rock-stable and 
could be used as a production platform.

Now, we're seeing that NFS is a second-class citizen (only that it is currently 
_impossible_ without modification of the FreeBSD system to have even one single 
NFS mount in your fstab(5) without risking certain eventual death for, being 
dropped into single-user mode).

The fact of the matter is that we use NFS to "band" our BSD systems together 
and without any modification to the FreeBSD system, we've identified no less 
than a half-dozen cases (that are _not_ extreme in any way) where the system 
boots into single-user mode.

But then again, I'm sure that you'll tell me that a simple power-outage is 
"extreme" -- in which case, even a power-outage can cause several hundreds of 
machines to boot into single-user mode simply because there was a 
race-condition between which machines would have DNS, which machines would have 
their "companion PC's" boot just a smidge slower than the machines that 
mount-them.



> If you can't figure
> out how to properly configure these systems,

We're resorting to insults now? Gee, thanks!



> then simply removing the script
> from /etc/rc.d is enough.

You reject my patch and tell me to "simply remov[e] the script". This confuses 
me. I would have in all earnest thought this was not a possible outcome. But 
hey... I guess that (removing the script) works too, just hadn't thought of it.

I'd still rather see the community embrace this simple patch. After-all, what's 
the harm if some administrator wants to disable this script? Like you say... 
deleting the script works too. But,... after deletion one cannot just "simply 
change his mind" ... as he now has to scp the script out from another box 
(which hopefully there's a copy lying around somewhere).

I think making the script toggle-able is better than just killing it (which is 
dirty as it leavers no easy way to turn it back on; in a general sense).



> 
> 2. Don't attempt to mount critical remote file systems using DNS names.

It doesn't matter if you use DNS names or not. If you don't use DNS names, then 
the box can still drop to single-user mode if the destination is not mountable. 
This can occur for example in a power-outage and the machines are not brought 
up in the right order or there is a momentary lapse caused by different 
boot-speeds of different hardware.

Trust me doug, we've been battling these cases for months.

The tiny two-line patch that is required to make mountlate toggle-able seems to 
be the "least evil" -- that is, including comparison to "simply removing the 
script" which in itself seems evil.



> This
> has been true for as long as I can remember. 

That may be so, but we at VICOR have the distinct impression that somewhere 
along the line between FreeBSD-4 (where we were extremely active -- hosting 
FreeBSD release parties at our office, contributing daily both monetarily and 
code-wise back when 3 committers were actively employed here) and -CURRENT, 
that NFS was made a "second-class citizen".

Back in the FreeBSD-4 days, we would have never imagined EVER making NFS 
critical to boot into single-user mode, because we know that NFS fails all the 
time and furthermore, we expect to SSH in and execute "mount -a" to fix the 
problem.

Mind you, I do see that there are a LOT of mechanisms for indicating via 
configuration that some network filesystem ought not to be critical to booting 
into multi-user mode, but in practice, not a damned one of them works. I've 
raised patches to fix "bg", I've raised patches to fix "late", and I've even 
suggested now that the "mountlate" mechanism be able to be disabled 
if-so-desired.

The net-effect to all of this, is that we feel that the community is actively 
trying to prevent progress-forward in finding a way to prevent a network 
filesystem from hanging the boot process, and we can't figure out WHY!!??

It's feeling like it's time to take this one to the forums.



> 
> 3. If you have critical remote systems that you can't afford to have hang
> in single user mode, put a serial console on them.

That's tantamount to a mandate to force our customers to build-out 
infrastructure that they currently (a) do not have and (b) do not desire.

Furthermore, we can't force our customers to do anything. If they say "no" to 
serial consoles, we can't force them.

That puts us in the unfortunate circumstance where we employ a field engineer 
that could gladly fix the problem remotely at 2AM via logging into sshd running 
in multi-user mode but alas... the system is stuck in single-user mode so the 
field engineer has to be dispatched at 2AM to go type a couple commands (which 
seems ridiculous).



> 
> Meta-notes:
> 
> 1. I obeyed your disclaimer text

I can't send e-mail without that being appended. I suggest you simply ignore it 
(the e-mail was directly addressed to the Gnats system and therefore the 
contents were _meant_ to be digested).



> and removed the second patch that you sent.
> 
> 2. It hasn't been "rcng" for a long time now. The preferred term is rc.d.

Thanks.


> 
> 
> Responsible-Changed-From-To: freebsd-rc->dougb
> Responsible-Changed-By: dougb
> Responsible-Changed-When: Sat Dec 31 07:54:00 UTC 2011
> Responsible-Changed-Why: 
> 
> I'm closing this.

Don't be surprised if it gets re-submitted.


> 
> http://www.freebsd.org/cgi/query-pr.cgi?pr=163727

-- 
Devin

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