Hi. I''m writing to the mailing list to know if Xen is what I''m looking for. I need a failover cluster with two completely and automatically replicated and redundanced servers running Windows Server 2003 Standard. Could Xen make this? Where I can found some information about making this configuration with Xen? Thank you very much for your help! Bye. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
shacky wrote:> Hi. > > I''m writing to the mailing list to know if Xen is what I''m looking for. > I need a failover cluster with two completely and automatically > replicated and redundanced servers running Windows Server 2003 > Standard. > Could Xen make this? > Where I can found some information about making this configuration with Xen? > > Thank you very much for your help! > > Bye. >Not..... exactly. You can keep multiple operating systems on a single server: you can migrate them from a common network storage to run on one server or another. But failover where one server''s operating system fails or is disabled, and another takes over the function, is a much more interesting thing to do. To do complete OS failover, every physical component must be mirrored and matched and the connections duplicated with failover redundancy, and that gets fascinating to support. It''s also amazingly expensive, much more than the cost of a small set of duplicate servers. If you have specific services running on those servers, you might be able to gracefully implement them in normal master/slave or master/master failover modes. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Wed, 31 Oct 2007, Nico Kadel-Garcia wrote:> shacky wrote: >> Hi. >> >> I''m writing to the mailing list to know if Xen is what I''m looking for. >> I need a failover cluster with two completely and automatically >> replicated and redundanced servers running Windows Server 2003 >> Standard. >> Could Xen make this? >> Where I can found some information about making this configuration with >> Xen? >> >> Thank you very much for your help! >> >> Bye. >> > Not..... exactly. You can keep multiple operating systems on a single > server: you can migrate them from a common network storage to run on one > server or another. But failover where one server''s operating system > fails or is disabled, and another takes over the function, is a much > more interesting thing to do. To do complete OS failover, every physical > component must be mirrored and matched and the connections duplicatedwhat? Even if "every component must be matched", that would be a GREAT reason to use XEN, as all the components are virtual, so of course they match. .. And using XEN underneath a proprietory O/S allows you to do things like replicate the filesystem via DRBD to another node... and/or make backups via snapshots, etc... So, while the question is incomplete, and XEN isn''t going to do the job by itself, it is a very usefull tool in getting the job done... as putting the proprietary OS inside a virtual machine gives you a degree of control you might not be able to get on physical hardware. I''ve got a couple of physical windows servers that I _wish_ were running inside virtual machines. That said, while I do use DRBD in production, I have not configured heartbeat to configure automated failover of services... nor do I make much use of windows. -Tom> with failover redundancy, and that gets fascinating to support. It''s > also amazingly expensive, much more than the cost of a small set of > duplicate servers.Nico, I like some of your answers... and some of them leave my mouth hanging open. You don''t leave yourself much wiggle room, it would be really easy for some newbie to think they were "the definitive" answers.> > If you have specific services running on those servers, you might be able to > gracefully implement them in normal master/slave or master/master failover > modes. > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users > >---------------------------------------------------------------------- tbrown@BareMetal.com | Always bear in mind that your own resolution to http://BareMetal.com/ | success is more important than any other one web hosting since ''95 | thing. - Abraham Lincoln _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
sadegh wrote:> > Hi All, > well , if we say FailOver mechanism is stop one and restart > another node it is true but if FailOver definition is Migration from > one node to another. > What is your idea about it?Slow down a moment. Failover means different things to different people. A full so-called "High Availability" solution, where each individual component can fail but the rest automatically switch the resources they''re using, is useful sometimes but seriously expensive to implement, and the switchover mechanisms themselves create their own uncertainties.> increasing redundant hardwares is it?It''s part of an integrated solution. The redundant hardware has to be cross-wired in usable failover setups for individual setups. Xen can be a very useful component for this, because the potentially more reliable centralized storage system can be made extremely robust and the servers swap domains as necessary to other working hardware.> and if we have proactive fault detection mechanism we can do it.Yes, but there are limits to this. Janitors blow fuses: cage monkeys accidentally crimp fiber, or disconnect idle connections. And hard drives fail without any warning whatsoever, even a few at a time. There''s a white paper from Google on this I highly recommend, where roughly 30% of the drives fail without any SMART detection at all.> some related works exist. > My thesis is about this subject "Improving Survivability of HA > Clusters" (that Mission-Critical apps. runs on...) > if any body help me to Hacking Xen, heartbeat and implementing some > other tools and compare results we can publishing some Papers about > this and have friendly work group! > I am ready to contribute and very appreciate. > Best Regards > SadeghOhhhh. Cool. It''s not clear how much you need Xen for this, as much as integration of Xen with the available approaches. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Tom Brown wrote:> On Wed, 31 Oct 2007, Nico Kadel-Garcia wrote: > >> shacky wrote: >>> Hi. >>> >>> I''m writing to the mailing list to know if Xen is what I''m looking >>> for. >>> I need a failover cluster with two completely and automatically >>> replicated and redundanced servers running Windows Server 2003 >>> Standard. >>> Could Xen make this? >>> Where I can found some information about making this configuration >>> with >>> Xen? >>> >>> Thank you very much for your help! >>> >>> Bye. >>> >> Not..... exactly. You can keep multiple operating systems on a single >> server: you can migrate them from a common network storage to run on >> one server or another. But failover where one server''s operating >> system fails or is disabled, and another takes over the function, is >> a much more interesting thing to do. To do complete OS failover, >> every physical component must be mirrored and matched and the >> connections duplicated > > what? Even if "every component must be matched", that would be a GREAT > reason to use XEN, as all the components are virtual, so of course > they match. > > .. And using XEN underneath a proprietory O/S allows you to do things > like replicate the filesystem via DRBD to another node... and/or make > backups via snapshots, etc... > > So, while the question is incomplete, and XEN isn''t going to do the > job by itself, it is a very usefull tool in getting the job done... as > putting the proprietary OS inside a virtual machine gives you a degree > of control you might not be able to get on physical hardware. I''ve got > a couple of physical windows servers that I _wish_ were running inside > virtual machines. > > That said, while I do use DRBD in production, I have not configured > heartbeat to configure automated failover of services... nor do I make > much use of windows. > > -Tom > >> with failover redundancy, and that gets fascinating to support. It''s >> also amazingly expensive, much more than the cost of a small set of >> duplicate servers. > > Nico, I like some of your answers... and some of them leave my mouth > hanging open. You don''t leave yourself much wiggle room, it would be > really easy for some newbie to think they were "the definitive" answers. > >> >> If you have specific services running on those servers, you might be >> able to gracefully implement them in normal master/slave or >> master/master failover modes. >> >> _______________________________________________ >> Xen-users mailing list >> Xen-users@lists.xensource.com >> http://lists.xensource.com/xen-users >> >> > > ---------------------------------------------------------------------- > tbrown@BareMetal.com | Always bear in mind that your own resolution to > http://BareMetal.com/ | success is more important than any other one > web hosting since ''95 | thing. - Abraham Lincoln > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users > > >Hi All, well , if we say FailOver mechanism is stop one and restart another node it is true but if FailOver definition is Migration from one node to another. What is your idea about it? increasing redundant hardwares is it? and if we have proactive fault detection mechanism we can do it. some related works exist. My thesis is about this subject "Improving Survivability of HA Clusters" (that Mission-Critical apps. runs on...) if any body help me to Hacking Xen, heartbeat and implementing some other tools and compare results we can publishing some Papers about this and have friendly work group! I am ready to contribute and very appreciate. Best Regards Sadegh _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Nico Kadel-Garcia wrote:> sadegh wrote: >> >> Hi All, >> well , if we say FailOver mechanism is stop one and restart >> another node it is true but if FailOver definition is Migration from >> one node to another. >> What is your idea about it? > Slow down a moment. Failover means different things to different > people. A full so-called "High Availability" solution, where each > individual component can fail but the rest automatically switch the > resources they''re using, is useful sometimes but seriously expensive > to implement, and the switchover mechanisms themselves create their > own uncertainties.Yes , i mean if we can freeze all of a context (context of processes of OS on a VM) on the shared storage for Live-Migration because of VMM is here then if some fault occurs migration to other host is practicable is it?>> increasing redundant hardwares is it? > It''s part of an integrated solution. The redundant hardware has to be > cross-wired in usable failover setups for individual setups. Xen can > be a very useful component for this, because the potentially more > reliable centralized storage system can be made extremely robust and > the servers swap domains as necessary to other working hardware.migrating to another non-utilized host (with some mechanisms) decreasing redundancy not all redundancy is it?>> and if we have proactive fault detection mechanism we can do it. > Yes, but there are limits to this. Janitors blow fuses: cage monkeys > accidentally crimp fiber, or disconnect idle connections. And hard > drives fail without any warning whatsoever, even a few at a time. > There''s a white paper from Google on this I highly recommend, where > roughly 30% of the drives fail without any SMART detection at all.hmmm. yes.>> some related works exist. >> My thesis is about this subject "Improving Survivability of HA >> Clusters" (that Mission-Critical apps. runs on...) >> if any body help me to Hacking Xen, heartbeat and implementing some >> other tools and compare results we can publishing some Papers about >> this and have friendly work group! >> I am ready to contribute and very appreciate. >> Best Regards >> Sadegh > Ohhhh. Cool. It''s not clear how much you need Xen for this, as much as > integration of Xen with the available approaches.i think the above words is clear thank you Sadegh> _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users > > >_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Hi, sadegh <mshoosh@comp.iust.ac.ir> wrote:> Nico Kadel-Garcia wrote: > > sadegh wrote: > >> > >> Hi All, > >> well , if we say FailOver mechanism is stop one and restart > >> another node it is true but if FailOver definition is Migration from > >> one node to another. > >> What is your idea about it? > > Slow down a moment. Failover means different things to different > > people. A full so-called "High Availability" solution, where each > > individual component can fail but the rest automatically switch the > > resources they''re using, is useful sometimes but seriously expensive > > to implement, and the switchover mechanisms themselves create their > > own uncertainties. > Yes , i mean if we can freeze all of a context (context of processes of > OS on a VM) on the shared storage for Live-Migration because of VMM is > here then if some fault occurs migration to other host is practicable > is it? > >> increasing redundant hardwares is it? > > It''s part of an integrated solution. The redundant hardware has to be > > cross-wired in usable failover setups for individual setups. Xen can > > be a very useful component for this, because the potentially more > > reliable centralized storage system can be made extremely robust and > > the servers swap domains as necessary to other working hardware. > migrating to another non-utilized host (with some mechanisms) decreasing > redundancy not all redundancy is it? > >> and if we have proactive fault detection mechanism we can do it. > > Yes, but there are limits to this. Janitors blow fuses: cage monkeys > > accidentally crimp fiber, or disconnect idle connections. And hard > > drives fail without any warning whatsoever, even a few at a time. > > There''s a white paper from Google on this I highly recommend, where > > roughly 30% of the drives fail without any SMART detection at all. > hmmm. yes. > >> some related works exist. > >> My thesis is about this subject "Improving Survivability of HA > >> Clusters" (that Mission-Critical apps. runs on...) > >> if any body help me to Hacking Xen, heartbeat and implementing some > >> other tools and compare results we can publishing some Papers about > >> this and have friendly work group! > >> I am ready to contribute and very appreciate. > >> Best Regards > >> Sadegh > > Ohhhh. Cool. It''s not clear how much you need Xen for this, as much as > > integration of Xen with the available approaches. > i think the above words is clear > thank youI am just sitting here, try to update the Xen OCF script from linux-ha, to add some xm mem-set statements to start, stop, migrate_, ... functions. I''ll see how far I get today, but you can contact me offlist if you want to get my updated script for tests. Sebastian _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users