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Virtualization Is Not All Roses
An anonymous reader writes "Vendors and magazines are all over virtualization like a rash, like it is the Saviour for IT-kind. Not always, writes analyst Andi Mann in Computerworld." I've found that when it works, it's really cool, but it does add a layer of complexity that wasn't there before. Then again, having a disk image be a 'machine' is amazingly useful sometimes.
I've found that VMware is incredibly useful for testing network booting (PXE) systems. I rolled my own custom Damn Small Linux for PXE booting on our thin client workstations. VMware was great for testing purposes. Everybody loves DSL too, they can listen to streaming audio and MP3s while they work too, since I included mplayer and Flash in Firefox. NX and FreeNX to connect to our terminal server.
Good story, but I disagree in some areas.
Bandwidth concerns. You can have more than one NIC installed on the server and have it dedicated to each virtual machine.
Downtime: If you need to do maintance on the host that may be a slight issue, but I hardly ever have to anything to the host. Also if the host is dying, you can shut donw the Virtual machine and copy it to another server (or move the drive) and bring it up fairly quickly. You also have cluster capability with virtualization.
Half of writing history is hiding the truth.
The absolute only place it has not been appropriate are locations requiring high amounts of disk IO. It has been a godsend everywhere else. All of our web servers, application servers, support servers, management servers, blah blah blah. It's all virtual now. Approximately 175 servers are now virtual. The rest are huge SQL Server/Oracle systems.
License controls are fine. All the major players support flexible VM licensing. The only people that bark about change control are those who simply don't understand virtual infrastructure and a good sit-down solved that issue. "Compliance" has not been an issue for us at all. As far as politics are concerned -- if they can't keep up with the future, then they should get out of IT.
FYI: We run VMware ESX on HP hardware (DL585 servers) connected to an EMC Clariion SAN.
Well, our Oracle servers are DL585's with four dual core cpu's, 32GB of ram, dual HBA's backed by an 112 disk SAN and they regularly max out both HBA's, trying to run that kind of load on a VM just doesn't make sense with the I/O latency and throughput degradation that I've seen with VMWare. I know I'm not the only one as I have seen this advice from a number of top professionals that I know and respect. If you have a lightly loaded SQL server or some AD controllers handling a small number of users then they might be good candidates, but any server that is I/O bound and/or spends a significant percentage of the day busy is probably the lowest priority to try to virtualize. You can probably get 99+% of the benefit of virtualization from the other 80-90% of your servers that are likely good candidates.
There are 4 boxes to use in the defense of liberty: soap, ballot, jury, ammo. Use in that order. Starting now.