Virtualization Plan Sanity Check

[dhicks]

Ultimately we cut corners on a physical to virtual conversion by way of not spending enough on the SAN (which was a repurposed Dell PowerEdge 2900) and are now feeling the pain of corrupted disks and non working VMs.

 

Why did you get corrupted disks? Do you mean you just had too many disks in your RAID array physically fail, or did something else happen?

[sted]

Differencing disks should allow for multiple instances based off the same parent disk in Hyper-V. The instances themselves will be 100% independent - the parent just gives them a common starting system installation rather than having to install twelve copies of the same OS and consume twelve times the disk space.

 

 

 

But it does mean you're using all the system resources of a full OS with GUI just in order to have that console - probably why Hyper-V requires such a scandalous amount of memory for itself.

 

 

 

Sadly not in KVM yet (at least not for Windows guests - Linux guests support balloon drivers and they're working on a Windows one).

 

again there is no ideal solution but i think its a bonus to be able to use the server as a console if things go pear shaped (always have a plan b at least) yes it wastes a bit of ram but its cheap enough these days that wasting 2gb is hardly the end of the world and if i ever dare sp1 the pc i wont even need to do that as such

 

Microsoft Hyper-V, VMWare vSphere Hypervisor (ESXi) and KVM are all free, and all perfectly fine for simple server virtualisation (except for KVM's lack of balloon drivers for Windows).

 

 

though bare metal hyper v is a pita to get started once going its fine but that first step i managed it once and like a fool diddnt document it and dont seem to able to replicate it lol

[Irazmus]

Hyper-V Server is free http://www.microsoft.com/hyper-v-ser...s/default.aspx (its a seprate thing from Windows Server) basicly Microsoft realised VMWare and Citrix were making a killing from 'free' products and they jumped on the band wagon.

Actually, to be nit-picky, Microsoft Hyper-V Server 2008 R2 is free - Microsoft Hyper-V Server: How to Get It, it's just that most people assume you can only get Hyper-V with Windows attached.

 

Doh! I stand corrected.

* Fetches dunces hat and goes to write lines in the corner

I will get my facts straight before nit-picking someone's comments.
I will get my facts straight before nit-picking someone's comments.
...

 

Just looking through your requirements again I don't think Debin works to well on Hyper-V so my bad on mentioning it.

No idea is a bad idea. With the exception of nit-picking without doing proper research first [facepalm]

 

It's important to remember that over-committing memory (ballooning) doesn't actually create more RAM from nowhere. Instead it'll grab memory back from machines which aren't using it by having a fake system driver request the memory - then it can be parcelled out to a machine which does need it at the time. Ballooning is good, paging to disk is a bad thing, and is what'll happen if too much over-committing goes on.

I was thinking of the print and web servers which will want generous amounts in exceptional circumstances (~100MB document or entire school accessing Moodle), but only moderate amounts during normal usage.

 

If I'm right, Ganeti doesn't do auto failover, but the LHAP does, so I should be able to combine the two to get the benefits of both. Either that or I'll end up with an unmanageable mess. But since full HA is desirable, not essential, it won't be the end of the world if I can't get it working.

 

No CALs needed.

Again I stand corrected.

Since I can't wear more than one dunces hat at once, I'll just have to wear it for twice as long.

 

And ESXi is Linux-based.

But I know my way around Debian better so I'll still stick with that, unless Gentoo tempts me away (fickle?)

[jamesfed]

Why did you get corrupted disks? Do you mean you just had too many disks in your RAID array physically fail, or did something else happen?

 

Just a faulty NIC on our makeshift SAN causing problems with iSCSI - the data transfered over fine but on booting the newly created VHDs just fried.

 

All working now though thanks for a new NIC and 2 days of watching backup tapes spin around in the auto loader (still coulda done without the hastle over the holiday)