On Wednesday 20 August 2008, Cedric Veilleux wrote: > 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? > when i converted our qmail system over, there was a noticable difference but i dont believe it was due to 64bit. qmail itself executed a bit faster due to better hardware,but there was a very noticable difference in executing the spam and anti-virus portions so in general the entire server was faster. so i think 64bit had some helping hand in this but how much i am not sure. > 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)... > it is a bit of work. i created a fresh 64bit guest, installed all packages then moved the configs and data over. was more time consuming to make sure i got everything than difficult. > 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 > -- Chuck