[Linux-cluster] Diskless Shared-Root GFS/Cluster

[Schaefer Christian]

Hello Tom,

>From my point ov view, the shared-root technology has several advantages compared with traditional approaches. And in my eyes it is worth beeing at the mercy of this "devastating problem" :).

As I learned about the shared root environment I was also a little bit confused, if this is really working as we migrated our webserver farm in 2005. But the last 2 years taught me, that it really works, and it really works good. To give you an idea of what we are doing: we are hosting about 70 different websites and applications such as shops and several backends with about 2.6 mio page impressions every month. The numbers tend to grow fast...

Another positiv aspect is administration: Imaging you only have to change a configuration file one time, not 6 or 10 times. Or backup can be achieved by tar'ing one single filesystem....

Yust ask the guys at atix.de, they can surely tell the story better than me abd know the technical aspects at a more detailed way than me. 

Best Regards, 

Christian Schäfer
System Engineer
Abt. IT-Applications
Messe München 

Tel.: +49 (0) 89 949 21985 
E-Mail: christian.schaefer2 at messe-muenchen.de 
WWW: www.messe-muenchen.de 

 

> -----Ursprüngliche Nachricht-----
> Von: linux-cluster-bounces at redhat.com 
> [mailto:linux-cluster-bounces at redhat.com] Im Auftrag von 
> Hagmann, Michael
> Gesendet: Mittwoch, 31. Januar 2007 21:08
> An: linux clustering
> Betreff: RE: [Linux-cluster] Diskless Shared-Root GFS/Cluster
> 
> When you come from the TruCluster side you will love it,like me.
> 
> But as Tom said is totaly diffrent and you should aware of, as example
> Human Error like delete the /etc or others.
> we implement for this reason ( as we do in our TruCluster 
> Enviroment ) a
> rsync based clone script. That mean we can clone with one Command the
> /boot and root to a "clone /boot" and a "clone root". In the 
> grub we add
> a entry to boot the clone, when someone also delete the 
> /boot, you have
> to change the /boot disk in the qlogic menu to the clone /boot.
> We also use this localclone, when we make a OS upgrade. First step is
> make a localclone and then upgrade the system. When you have trouble
> during the upgrade you always have the chance to boot the 
> localclone and
> you have a working cluster. It's also great when you have done the
> upgrade and a few days later a big Problem ocoured, you can 
> reboot into
> the localclone and have a working cluster. 
> 
> What I wan't say is we are aware of this Problem ( because we use it
> long time ) and we handle that with spez. Processes and Tools. The
> Shared-Root it's a diffrent approach, like TruCluster and OpenVMS.
> 
> We love it
> 
> Mike
> 
> -----Original Message-----
> From: linux-cluster-bounces at redhat.com
> [mailto:linux-cluster-bounces at redhat.com] On Behalf Of Tom Mornini
> Sent: Mittwoch, 31. Januar 2007 10:26
> To: linux clustering
> Subject: Re: [Linux-cluster] Diskless Shared-Root GFS/Cluster
> 
> We strongly considered this when implementing our cluster
> infrastructure, but decided against it when we realized just how
> devastating *any* problem with that shared root would be...
> 
> -- 
> -- Tom Mornini, CTO
> -- Engine Yard, Ruby on Rails Hosting
> -- Reliability, Ease of Use, Scalability
> -- (866) 518-YARD (9273)
> 
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