Subject: Re: [vserver] Pros and Cons of 32/64bit guests on 64bit host
From: Cedric Veilleux <cveilleux@neopeak.com>
Date: Wed, 20 Aug 2008 17:13:45 -0400
Wed, 20 Aug 2008 17:13:45 -0400
Hi,

> As I have to update the guests anyway (I used and will use gentoo for
> them), so I am considering to move them to 64bit, too. The guests are
> several LAMP servers, mysql and postgres and a set of qmail nodes.
> 
> The only issue that is an obvious go for 64bit would be memory segments
> >3GB, but I guess I wont have guests who use it. So, anybody here can
> give pros and cons for 32/64 bit guests?

I recently did pretty much the same thing, migrate a bunch of 32 bit
guests to new 64 bit based hosts and it went very well.

32 bit guest will be just as stable in a 64 bit host than in a 32 bit
one. So stability is not a problem.

Other than that, you are already aware of the memory limit advantage of
64 bit guests.. not really useful for most guests indeed..

The last advantage of 64 bit is performance, some applications will
perform better in 64 bit (while others seem to do worse).. For LAMP /
QMail, I doubt there is a big speed difference.. Anybody can confirm
that?

If you are just migrating an existing 32 bit guest, converting it to 64
bit will be a lot of work, as there is essentially no distribution that
supports such upgrade path (AFAIK)...

Personnaly, I am slowly phasing out 32 bit guests in favor of 64 bit
ones, but the conversion to 64 bit is never the real reason behind the
move. It just seems logical to me to create new vservers as 64 bit and
keep the old ones in 32 bit until there is a real reason to upgrade
them.


Cedric


["application/x-pkcs7-signature" not shown]