High avalibility
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5 เมษายน 2550 12:32
Hi
The main thing that I like about VmWare ESX is how easy it is to create a high availibility setup because of vmfs. Just create a LUN, place your virtual machines on that LUN, and give your hosts access to that LUN.
From what I understand with virtual server, you have to create a LUN for each virtual server, and then the cluster will move ownership of that LUN between the servers when a failover occours. How is HA going to work in Veridian? Do you still have to do a cluster setup with a LUN for each virtual server you want to be able to move between the physical hosts?
Regards,
Kaj
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14 เมษายน 2550 14:02
That's an interesting point.
In my very own opinion this is one of the few features Viridian will not be able to catch up VMware with (but I might be wrong). The real advantage VMware has in this space is that VMFS is a cluster file system where exclusive access for a given host is given to the file (i.e. the virtual disk) and not to the whole partition. NTFS is not (at least not today) capable of doing that.
It is my understanding that you either do what you have mentioned (an alternative would be to put more vm's into the single NTFS datastore but in that case the single unit of failover would not be the single VM but the entire Group) or it is my understanding that MS will be able to give you the flexibility to do what you do today with VMware using a network share. Incidentally the Network Share has the same characteristics of a cluster file system (i.e. it can be shared simulatneously by more physical hosts and the lock is per-file and not per-volume).
The drawback is performance since NTFS/VMFS are accessed at block level while a Network Share (as the name implies) is accessed at file level (that is via the wholeTcp-ip stack).
Consider this is my understanding and I might very well be proven wrong when we see the bits. If others have a better understanding of the matter please let us know.
Massimo.
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21 เมษายน 2550 16:33
Windows Server virutalization will have excellent high availability capabilities. First, Windows Server virtualization is cluster aware out of the box so configuration will be a snap. Second, clustering is standard offering in Windows Server Enterprise and Datacenter Editions so it's all built in. Furthermore, there are a number of major enhancements in clustering in Windows Server "Longhorn" for clustering that allow it to scale better than ever before. (More on this to come...)
As for clustered versus non-clustered file systems, Windows Server virtualization will be able to run fine in both environments whether it's NTFS or a third party files system like SANbolic or PolyServe.
Cheers,
-Jeff
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