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My ramblings on the stuff that holds it all together
Note to remember, don’t forget to check the duplex settings on NICs handling your vMotion traffic.
My updated clustered ESX test lab is progressing (more posts on that in the next week or so)… and I’m kind of limited in that I only have an old 24-port 100Mb Cisco hub for the networking at the moment.
vMotion warns about the switch speed as a possible issue.
I had my Service Console/ vMotion NICit forced to 100/full and when I 1st tried it vMotion took 2hrs to get to 10%, I changed it to auto-negotiate whilst the task was running and it completed without breaking the vMotion task ain a couple of seconds, dropped only 1 ping to the VM I moved.
Cool, it’s not production or doing a lot of workload but useful to know despite the warning it will work even if you’ve only got an old hub for your networking, and worth remembering that Duplex mis-matches can literally add hours and days onto network transfers.
If you deploy your VM’s from a master image using Virtual Center’s Deploy from template functionality (below).
When you try and delete a virtual machine you’ve created from disk
You get the following prompt
Are you sure you want to delete this VM and it’s associated base disk?
Please note if other VMs are sharing this base disk, they will no longer have access to this disk.
This does not refer to the master VM image you deployed from; in other words if you delete the VM it does not break all other VMs deployed from the initial template.
One other point to note, when you perform “Deploy virtual machine from template” operation, the target field (below) is actually the name of the base image you are cloning, rather than the name of the eventual VM you are creating from it – odd, but that’s how it is (below)
You’ve been able to buy solid state SAN technology like the Tera-RAMSAN from TMS which gives you up to 1Tb of storage, presented over 4Gb/s fibre channel or Infiniband @10Gb/s… with the cost of flash storage dropping its going to soon fall in to the realms of affordability (from memory a year ago 1Tb SSD SAN was about £250k, so would assume that’s maybe £150k now – would be happy to see current pricing if anyone has it though).
If you were able to combine this with a set of ESX hosts dual-connected to the RAMSAN and traditional equipment (like an HP EVA or EMC Clariion) over a FC or iSCSI fabric then you could possibly leverage the new Storage vMotion features that are included in ESX 3.5 to achieve a 2nd level of performance and load levelling for a VM farm.
It’s pretty common knowledge that you can use vMotion and the DRS features to effectively load level or average VM CPU and memory load across a number of VMWare nodes within a cluster.
Using the infrastructure discussed above could add a second tier of load balancing without downtime to a DRS cluster. If a VM needs more disk throughput or is suffering from latency then you could move them to/from the more expensive solid-state storage tiers to FC-SCSI or even FATA disks, this ensures you are making the best use of fast, expensive storage vs. cheap, slow commodity storage.
Even if Virtual Center doesn’t have a native API for exposing this type of functionality or criteria for the DRS configuration you could leverage the plug-in or scripting architecture to use a manager of managers (or here) to map this across an enterprise and across multiple hypervisors (Sun, Xen, Hyper V)
I also see EMC integrating flash storage into the array itself, would be even better if you could transparently migrate LUNS to/from different arrays and disk storage without having to touch ESX at all.
Note: This is just a theory I’ve not actually tried this – but am hoping to get some eval kit and do a proof on concept…
I’ve been really busy the last couple of weeks and I’ve had to trim down my incoming RSS feeds, as there was too much noise and I was missing important things like the following;
VMWare are shaping up to have a really good set of management tools – lab and site recovery manager are of particular interest to me for several projects I’m working on.
or “How to convert virtual centre from evaluation to licenced version”… for us Brits… the “American English” is to help the international Googlers 🙂
I can’t believe I missed this, on a couple of platforms I’ve built I’ve had to start with an eval licence and then move to a proper licence but could never find how to change virtual center from eval to licenced mode.
ESX itself was fine you can do that via the VC GUI (below)
But despite a lot of googling I could never find out how to set Virtual Centre itself to use a licence server – so I ended up reinstalling/repairing and then selecting the option to use a licence server, my bad – it’s actually in the VI client GUI d’oh as Homer would say!
for my own reference, and for anyone else who has missed and is searching for how to convert Virtual Center from evaluation to licensed..
and then configure the setting here to point it at a proper licence server to enable full VC.
Martin’s post here prompted me to blog something I’ve been meaning to do for a while.
Virtualization projects and services are cool; we all understand the advantages in power/cooling and the flexibility it can bring to our infrastructures.
But what about support, if you are a service provider (internal or outsourcing) you normally need to be able to offer an end-end SLA on your services. typically this would be backed off against a vendor like Microsoft or Oracle via one of their premium support arrangements.
From what I see in the industry, with most software vendors especially Microsoft there is almost no way a service provider can underwrite an SLA as application/OS vendors give themselves significant scope to say “unsupported configuration” if you are running it under a hypervisor or other VM technology… Microsoft use the term commercially reasonable in their official policy – who decides what this is?
I would totally accept that a vendor would not guarantee performance under a hypervisor – that’s understandable and we have tools to analyse, monitor and improve (Virtual Centre, MOM, DRS, increase resources etc.). but too many vendors seem to use it as a universal “get out of jail free card”.
Issues of applications with dependency on physical hardware aside (fax cards, realtime CPU, DSP, PCI cards etc.) In my entire career working with VM technology I’ve only ever seen one issue that could be directly attributed to being caused by virtualization – and to be fair that was really a VMTools issue; rather than VMWare itself.
Microsoft have an official list of their applications that are not supported here – why is this? speech server I could maybe understand as it would probably be timer/DSP sensitive – but the rest? Sharepoint? I know for a fact ISA does work under VMWare as I use it all the time.
Microsoft Virtual Server support policy http://support.microsoft.com/kb/897613
Support policy for Microsoft software running in non-Microsoft hardware virtualization software http://support.microsoft.com/kb/897615/
Exchange is specifically excluded (depending on how you read the articles)
· On the Exchange Server 2007 System requirements page it only mentioned Unified messaging as being unsupportable in a virtual environment http://technet.microsoft.com/en-us/library/aa996719.aspx
· Yet on TechNet it is clear stated that “Neither Exchange 2007 nor Exchange 2007 SP1 is supported in production in a virtual environment” http://technet.microsoft.com/en-us/library/bb232170(EXCHG.80).aspx
Credit due to a colleague for pulling together the relevant Microsoft linkage
But I know it….
a) works fully – I do it all the time.
b) Lots of people are doing this in production with lots of users (many people at VMWorld US last year)
c) VMWare have a fully-supportable x64 hypervisor – It’s just MS that don’t
What is the industry going to do about this?, I asked this question of peers a lot at VMWorld and at BriForum; and to be honest everyone has the same concern but have a few different approaches;
Dont’ tell/ask – 99% of the time a tech support rep won’t know its running under VMWare/a.n.other hypervisor so why complicate matters by telling them – could of course back-fire on you!
Threaten – “If you won’t support under VMWare we’ll use one of your competitors applications”; however this only really works if you are the US govt. or Globocorp Inc. or operate in a very niche application market.
Mitigate – reflect this uncertainty in an SLA, best-endeavours etc. this would kill most virtualization efforts in their tracks for an enterprise customer.
The same support issue has been around for a long time; Citrix/Terminal Services, application packaging, automated installations, etc. are treated as “get out of jail free cards” by support organisations…
But whilst there are some technical constraints (usually only affecting badly written apps) with terminal services and packaging, virtualization changes the game and should make it simpler for a vendor to support as there is no complex runtime integration with a host OS + bolt-ons/hacks it’s just an emulated CPU/disk/RAM you can do whatever you like within it.
So – the open debate; what do you do? and how do you manage it?
There is a new site here (disclaimer: it does seem to be promoting a commercial service, but has some useful information that has been put into the public domain); describing some methods to roll your own P2V backup approach; I’ve not read in detail yet; but looks like Frane Borozan has solved some of the challenges I’ve encountered in the past automating the Free VMWare Convertor tool.
When I get some time I will revisit my build a better test lab series (and update it!) I hope to be able to integrate some of Frane’s ideas.
Thanks to Techhead for passing on the link; we worked together on the platform underlying the Build a better test lab series and he did a lot of work on the P2V and post-P2V automation tasks – he’s got a lot of handy scripts for doing this on an HP platform
Virtualized DR is going to be big this year; I have a long line of customers with this high on their list of priorities… Both for cross site 100% VMWare implementations and for the ability to backup/restore physical platforms to VMWare grid in a DR situation.
It just makes so much sense; no delay whilst racking & stacking recovery kit or problems restoring to different hardware etc. your admin’s can even do it from home – which can have some significant advantages in the event of a natural disaster like Katrina or floods like we had over the last couple of years in the UK
PlateSpin Forge is something we are seriously looking at as well as Symantec Backup Exec System Recovery Server Edition (who win a prize for extending the longest, most annoying product name! despite acquiring it from Veritas).
Will be an interesting year; I’m sure Sungard and all those recovery centre facilities will be moving to a grid/resource rental model rather than pure rack/floor space and retained hardware on-contract.
I’ve not done anything with my home ESX server this week as I’ve been busy with work; so this will be interesting – it’s been powered up all the time with all the VM’s spinning; but not doing very much.
Whist running this set of VMs.. (the CPU stats for VMEX01 and VMEX02 are a bit skewed as I added this bit after the original post and they are both running seti@home (hence increased CPU)
So, nothing interesting to see here – but might be worth bearing in mind for some kind of sizing estimate; this is a single core CPU (HT enabled) PC with 4Gb RAM and a single 500Gb SATA disk
Hopefully I will get some time this week to load up SETI@Home or Folding@Home and see what that does 🙂 it should be a good test to see how well the hypervisor manages CPU timesharing between hosts.