ReiserFS and general cyrus filesystem usage information - was Re: best filesystem for imap server

[Henrique de Moraes Holschuh]

On Fri, 03 Dec 2004, Igor Brezac wrote:
> On Thu, 2 Dec 2004, Henrique de Moraes Holschuh wrote:
> >series is *not* to be trusted yet.  It is not just because of Cyrus (after
> >all, a bug in Cyrus code might cause BDB 4.x to misbehave),
> 
> This Cyrus bug has been fixed a long time ago.  I've run cyrus with BDB 
> 4.1 or higher for almost two years without any issues.

I do think I've read not so much time ago in this ML (certainly no more than
a few months) that there *could* be a well hidden bug still lurking in the
BDB code.

It would be a good idea to read all the 4.2 docs and do a full functionality
audit of the code sometime.

> stories, but there are numerous folks who run OpenLDAP with great success 
> in very busy environments.

Heh, I am one of those that got burned by older BDB 4.2 buggy code when
multiple databases are in use in the same environment in a SMT or SMP box
(SMT triggered the bug sooner than SMP; SMT+SMP triggered it almost always,
as soon as writes started).

The thing's running stable for a couple of months now, so I hope the issue
is completely fixed (at least within Debian. We *do* have patches to 4.2.52
to make it so, I don't know if these are available at the Sleepycat site).

I wonder how many of the reports of crashes and trouble with BDB are due to
people trying to use vendor-supplied BDB 4.x builds that haven't got the
latest patches, or known-bad BDB releases...

BTW, I regard BDB 4 and BDB 4.1 as certain-data-corruption-will-happen
territory.  IMHO Cyrus' autoconf script should refuse to work with anything
but BDB 3.2, 4.2 and 4.3 (when we test 4.3 enough, that is).

> >>default values for important settings, data corruption *will* happen.
> >Indeed.
> 
> A correctly configured BDB 4.x environment will behave and perform well. 
> I am yet to corrupt a BDB database to a point where the data is not 
> recoverable.

Well, same here I *think*. I recall doing some rm -rf <database directory>
type restores from LDIF to OpenLDAP, but I don't recall why I did it that
way.

> For those interested, you can find BDB docs at 
> http://www.sleepycat.com/docs/ref/toc.html.  As Henrique pointed out, BDB 
> is very complex, but it can also do a very good job.

Exactly, which is why we tolerate it :P

-- 
  "One disk to rule them all, One disk to find them. One disk to bring
  them all and in the darkness grind them. In the Land of Redmond
  where the shadows lie." -- The Silicon Valley Tarot
  Henrique Holschuh
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