[Zope] Zope Myths?

tomas@fabula.de tomas@fabula.de
Thu, 12 Sep 2002 08:21:52 +0200


On Wed, Sep 11, 2002 at 03:46:43PM -0700, sean.upton@uniontrib.com wrote:
> I strongly considered this option at one time with a shared DAS/RAID between
> my primary and secondary ZSS.  I never ended up doing this because of
> concerns.
> 
[...]

> It really seems like replication is really a less brittle option (though how
> much less brittle, I'm not sure).
> 

Hear, hear... Besides, you still have a single point of failure: your SAN
system. OK, it's expensive and may thus fail less, but then you might buy
an expensive system to begin with ;-)

Another experience I had with such semi-high-end thingies is: if you haven't
(some access to) experience with this very configuration, unexpected problems
tend to crop up, thus eating up the advantage you thought to have. You are
dealing with a more exotic system, with a smaller installed base, remember.
You better know you understand very well how it works (or you have access to
someone who does). Don't believe what marketing says -- those guys are in
bed when one of your SCSI disks in the array fails and the RAID controller
thinks it hasn't a hot spare and it'd better shut down the system (I had this
one too -- luckyly I don't sell myself as hardware guy ;-)

> Though not committed at this point, for a big project I am working on, I am
> strongly considering use of DirectoryStorage and its snapshot capabilities
> for low-tech replication (via find+cpio+nfs) to try and minimize issues I
> might face similar to #2 and #3 if I had chosen FileStorage.

I'd tend myself too to low-tech replication solutions -- in spite of the
issues they present. Besides, if the systems are far apart, they still
work if one of the buildings catches fire =:-0

Cheers
-- tomas