Designing a Reliable Web Application
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@scottalanmiller said in Designing a Reliable Web Application:
@thwr said in Designing a Reliable Web Application:
Don't know if KVM or Xen can do active standby VM's (mirrored VMs) like VMWare, at least Hyper-V can't do that (as of 2012R2)
Do you mean shared memory where there is full fault tolerance and absolutely zero downtime and zero crash consistency issues? Then no, no one does that except for VMware right now. It's the biggest feature that I think makes VMware worth it for shops that need VMware. But it is a massively expensive feature both in terms of VMware licensing as well as in terms of performance hits, OS licensing and system overhead. Doing memory mirroring across nodes is very, very painful in terms of system resources.
Exactly. It's like a RAID-1-ish VM.
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@thwr said in Designing a Reliable Web Application:
@scottalanmiller said in Designing a Reliable Web Application:
@thwr said in Designing a Reliable Web Application:
Don't know if KVM or Xen can do active standby VM's (mirrored VMs) like VMWare, at least Hyper-V can't do that (as of 2012R2)
Do you mean shared memory where there is full fault tolerance and absolutely zero downtime and zero crash consistency issues? Then no, no one does that except for VMware right now. It's the biggest feature that I think makes VMware worth it for shops that need VMware. But it is a massively expensive feature both in terms of VMware licensing as well as in terms of performance hits, OS licensing and system overhead. Doing memory mirroring across nodes is very, very painful in terms of system resources.
Exactly. It's like a RAID-1-ish VM.
Yeah, that's a VMware exclusive. Not very applicable to the SMB market, but when you need it that's my top pick for "when to look at VMware." It's the most significant (to me anyway) "only on Vmware" feature. Most other things that VMware does well are soft benefits, like better memory management, but you might be able to offset that by just buying more memory on another platform. It's not a pure win. But their shared memory fault tolerance is an absolute win. When you need it, you either leave the commodity server world completely or you use VMware.
@John-Nicholson can talk more about that as well.
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@scottalanmiller said in Designing a Reliable Web Application:
@thwr said in Designing a Reliable Web Application:
@scottalanmiller said in Designing a Reliable Web Application:
@thwr said in Designing a Reliable Web Application:
Don't know if KVM or Xen can do active standby VM's (mirrored VMs) like VMWare, at least Hyper-V can't do that (as of 2012R2)
Do you mean shared memory where there is full fault tolerance and absolutely zero downtime and zero crash consistency issues? Then no, no one does that except for VMware right now. It's the biggest feature that I think makes VMware worth it for shops that need VMware. But it is a massively expensive feature both in terms of VMware licensing as well as in terms of performance hits, OS licensing and system overhead. Doing memory mirroring across nodes is very, very painful in terms of system resources.
Exactly. It's like a RAID-1-ish VM.
Yeah, that's a VMware exclusive. Not very applicable to the SMB market, but when you need it that's my top pick for "when to look at VMware." It's the most significant (to me anyway) "only on Vmware" feature. Most other things that VMware does well are soft benefits, like better memory management, but you might be able to offset that by just buying more memory on another platform. It's not a pure win. But their shared memory fault tolerance is an absolute win. When you need it, you either leave the commodity server world completely or you use VMware.
@John-Nicholson can talk more about that as well.
Hyper-V 's memory management is also awesome, IMHO. But you are right, the gap between VMware and the other major players is getting smaller and smaller with every release cycle. It's next to non-existing as of today. Remember very well when people laughed at me a few years ago for choosing Hyper-V to replace an existing VMware vSphere EP environment. I have yet to regret it.
