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Virtualization, Cloud, Infrastructure and all that stuff in-between

My ramblings on the stuff that holds it all together

Category Archives: blade

Virtualization – the key to delivering "cloud based architecture" NOW.

 

There is a lot of talk about delivering cloud or elastic computing platforms, a lot of CxO’s are taking this all in and nodding enthusiastically, they can see the benefits.. so make it happen!….yesterday.

Moving your services to the cloud, isn’t always about giving your apps and data to Google, Amazon or Microsoft.

You can build your own cloud, and be choosy about what you give to others. building your own cloud makes a lot of sense, it’s not always cheap but its the kind of thing you can scale up (or down..) with a bit of up-front investment, in this article I’ll look at some of the practical; and more infrastructure focused ways in which you can do so.

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Your “cloud platform” is essentially an internal shared services system where you can actually and practically implement a “platform” team that operates and capacity plans for the cloud platform; they manage it’s availability and maintenance day-day and expansion/contraction.

You then have a number of “service/application” teams that subscribe to services provided by your cloud platform team… they are essentially developers/support teams that manage individual applications or services (for example payroll or SAP, web sites etc.), business units and stakeholders etc.

Using the technology we discuss here you can delegate control to them over most aspects of the service they maintian – full access to app servers etc. and an interface (human or automated) to raise issues with the platform team or log change requests.

I’ve seen many attempts to implement this in the physical/old world and it just ends in tears as it builds a high level of expectation that the server/infrastructure team must be able to respond very quickly to the end-“customer” the customer/supplier relationship is very different… regardless of what OLA/SLA you put in place.

However the reality of traditional infrastructure is that the platform team can’t usually react as quick as the service/application teams need/want/expect because they need to have an engineer on-site, wait for an order and a delivery, a network provisioning order etc. etc (although banks do seems to have this down quite well, it’s still a delay.. and time is money, etc.)

Virtualization and some of the technology we discuss here enable the platform team to keep one step ahead of the service/application teams by allowing them to do proper capacity planning and maintain a pragmatic headroom of capacity and make their lives easier by consolidating the physical estate they manage. This extra headroom capacity can be quickly back-filled when it’s taken up by adopting a modular hardware architecture to keep ahead of the next requirement.

Traditional infrastructure = OS/App Installations

  • 1 server per ‘workload’
  • Silo’d servers for support
  • Individually underused on average = overall wastage
  • No easy way to move workload about
  • Change = slow, person in DC, unplug, uninstall, move reinstall etc.
  • HP/Dell/Sun Rack Mount Servers
  • Cat 6 Cables, Racks and structured cabling

The ideal is to have an OS/app stack that can have workloads moved from host A to host B; this is a nice idea but there are a whole heap of dependencies with the typlical applications of today (IIS/apache + scripts, RoR, SQL DB, custom .net applications). Most big/important line of business apps are monolithic and today make this hard. Ever tried to move a SQL installation from OLD-SERVER-A to SHINY-NEW-SERVER-B? exactly. *NIX better at this, but not that much better.. downtime required or complicated fail over.

This can all be done today, virtualization is the key to doing it – makes it easy to move a workload from a to b we don’t care about the OS/hardware integration – we standardise/abstract/virtualize it and that allows us to quickly move it – it’s just a file and a bunch of configuration information in a text file… no obscure array controller firmware to extract data from or outdated NIC/video drivers to worry about.

Combine this with server (blade) hardware, modern VLAN/L3 switches with trunked connections, and virtualised firewalls then you have a very compelling solution that is not only quick to change, but makes more efficient use of the hardware you’ve purchased… so each KW/hr you consume brings more return, not less as you expand.

Now, move this forward and change the hardware for something much more commodity/standardised

Requirement: Fast, Scalable shared storage, filexible allocation of disk space and ability to de-duplicate data, reduce overhead etc, thin provisioning.

Solution: SAN Storage, EMC Clariion, HP-EVA, Sun StorageTek, iSCSI for lower requirements, or storage over single Ethernet fabric – NetApp/Equalogic

Requirement: Requirement Common chassis and server modules for quick, easy rip and replace and efficient power/cooling.

Solution: HP/Sun/Dell Blades

Requirement: quick change of network configurations, cross connects, increase & decrease bandwidth

Solution: Cisco switching, trunked interconnects, 10Gb/bonded 1GbE, VLAN isolation, quick change enabled as beyond initial installation there are fewer requirements to send an engineer to plug something in or move it, Checkpoint VSX firewalls to allow delegated firewall configurations or to allow multiple autonomous business units (or customers) to operate from a shared, high bandwidth platform.

Requirement: Ability to load balance and consolidate individual server workloads

Solution: VMWare Infrastructure 3 + management toolset (SCOM, Virtual Centre, Custom you-specific integrations using API/SDK etc.)

Requirement: Delegated control of systems to allow autonomy to teams, but within a controlled/auditable framework

Solution: Normal OS/app security delegation, Active Directory, NIS etc. Virtual Center, Checkpoint VSX, custom change request workflow and automation systems which are plugged into platform API/SDK’s etc.

the following diagram is my reference architecture for how I see these cloud platforms hanging together

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As ever more services move into the “cloud” or the “mesh” then integrating them becomes simpler, you have less of a focus on the platform that runs it – and just build what you need to operate your business etc.

In future maybe you’ll be able to use the public cloud services like Amazon AWS to integrate with your own internal cloud, allowing you to retain the important internal company data but take advantage of external, utility computing as required, on demand etc.

I don’t think we’ll ever get to.. (or want) to be 100% in a public cloud, but this private/internal cloud allows an organisation to retain it’s own internal agility and data ownership.

I hope this post has demonstrated that whilst, architecturally “cloud” computing sounds a bit out-there, you can practically implement it now by adopting this approach for the underlying infrastructure for your current application landscape.

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HP Rapid Deployment Pack – PXE Settings for Deploying Windows OS

 

The followign screens show a working configuration from the RDP 3.80 PXE Configuration Manager

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Have had lots of problems with this deploying Windows OS’es and VMWare ESX 3.5 onto an HP c7000 Blade chassis, still not resolved all the problems, but this definitely works for deploying Windows!

The documentation reads like you should always use the Linux PE configuration and it handles switching between WinPE/LinuxPE depending on which OS job you drop on a target. in my experience this doesn’t work and you need to manually change the PXE configuration to default to LinuxPE or WinPE depending on the OS you want to target.

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And

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Still a work in progress as I have a c7000 to which I want to deploy a mix of Windows and ESX/Redhat OS’es….

I did get a previous installation to install ESX 3.5 by hacking the default ESX 3.02 job, but its since been re-installed and I can’t do it now

RDP 6.90 seems to list Windows 2008 and ESX 3.5 in the quickspecs, but I’ll be damned if I can find where to download it, going to have to call HP methinks!

As I’ve posted before installing via iLo is just a non-starter if you really do want a flexible and fast deployment configuration – so it has to be RDP.

More later…

How does an HP Fibre Channel Virtual Connect Module Work?

 

Techhead and I have spent a lot of time recently scratching our heads over how and where fibre channel SAN connections go in a c7000 blade chassis.

If you don’t know, a FC-VC module looks like this, and you install them in redundant pairs in adjacent interconnect bays at the rear of the chassis.

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You then patch each of the FC Ports into a FC switch.

The supported configuration is one FC-VC Module to 1 FC switch (below)

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Connecting one VC module to more than one FC switch is unsupported (below)

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So, in essence you treat each VC module as terminating all HBA Port 1’s and the other FC-VC module as terminating all HBA Port 2’s.

The setup we had:

  • A number of BL460c blades with dual-port Qlogic Mezzanine card HBAs.
  • HP c7000 Blade chassis with 2 x FC-VC modules plugged into interconnect bay 3 & 4 (shown below)

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The important point to note is that whilst you have 4 uplinks on each FC-VC module that does not mean you have 2 x 16Gb/s connection “pool or trunk” that you just connect into.

Put differently if you unplug one, the overall bandwidth does not drop to 12Gb/s etc. it will disconnect a single HBA port on a number of servers and force them to failover to the other path and FC-VC module.

It does not do any dynamic load balancing or anything like that – it is literally a physical port concentrator which is why it needs NPIV to pass through the WWN’s from the physical blade HBAs.

There is a concept of over-subscription, in the Virtual Connect GUI that’s managed by setting the number of uplink ports used.

Most people will probably choose 4 uplink ports per VC module, this is 4:1 oversubscription, meaning each FC-VC port (and there are 4 per module) has 4 individual HBA ports connected to it, if you reduce the numeber of uplinks you increase the oversubscription (2 uplinks = 8:1 oversubscription,  1 uplink = 16:1 oversubscription)

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Which FC-VC Port does my blade’s HBA map to?

The front bay you insert your blade into determines which individual 4Gb/s port it maps to and shares with other blades) on the FC-VC module, its not just a virtual “pool” of connections, this is important when you plan your deployment as it can affect the way failover works.

the following table is what we found from experimentation and a quick glance at the “HP Virtual Connect Cookbook” (more on this later)

FC-VC Port Maps to HBA in Blade Chassis Bay, and these ports are also shared by..
Bay3-Port 1, Bay-4-Port 1 1,5,11,15
Bay3-Port 2, Bay-4-Port 2 2,6,12,16
Bay3-Port 3, Bay-4-Port 3 3,7,9,13
Bay3-Port 4, Bay-4-Port 4 4,8,10,14

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Each individual blade has a dual port HBA, so for example the HBA within the blade in bay 12 maps out as follows

HBA Port 1 –> Interconnect Bay 3, Port 2

HBA Port 2 –> Interconnect Bay 4, Port 2

 

Looking at it from a point of a single SAN attached Blade – the following diagram is how it all should hook together

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 Path Failover

Unplugging an FC cable from bay 3, port 4 will disconnect one of the HBA imageconnections to all of the blades in bays 4,8,10 and 14 and force the blade’s host OS to handle a failover to its secondary path via the FC-VC module in bay 4.

 

A key take away from this is that your blade hosts still need to run some kind of multi-pathing software, like MPIO or EMC PowerPath to handle the failover between paths – the FC-VC modules don’t handle this for you.

 

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FC Loading/Distribution

A further point to take away from this is that if you plan to fill your blade chassis with SAN attached blades, each with an HBA connected to a pair of FC-VC modules then you need to plan your bay assignment carefully based on your server load.

Imagine if you were to put heavily used SAN-attached VMWare ESX Servers in bays 1,5,11 and 15 and lightly used servers in the rest of the bays then you will have a bottleneck as your ESX blades will all be contending with each other for a single pair of 4Gb/s ports  (one on each of the FC-VC modules) whereas if you distributed them into (for example) bays 1,2,3,4 then you’ll spread the load across individual 4Gb/s FC ports.

Your approach of course may vary depending on your requirements, but I hope this post has been of use.

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There is a very, very useful document from HP called the HP Virtual Connect Fibre Channel Cookbook that covers all this in great detail, it doesn’t seem to be available on the web and the manual and online documentation don’t seem to have any of this information, if you want a copy you’ll need to contact your HP representative and ask for it.

Cisco ASR is Virtual to the Core, all 40 of them!

 

Interesting article here on how Cisco have made heavy use of virtualization within their new ASR series router platform, Linux underneath and 40 core CPUs!

This type of approach does make me wonder if we will get to the stage of running traditional “network” and “storage” services as VM’s under a shared hypervisor with traditional “servers”.. totally removing the dependency on dedicated or expensive single-vendor hardware.

Commodity server blade platforms like the HP or Sun blade systems are so powerful these days, with flexible interconnect/expansion options this type of approach makes a lot of sense to me and is totally flexible.

Maybe one day it will go the other way and all your Windows boxen will run inside a Cisco NX7000 lol!

On reflection maybe all those companies have too much of a vested interest in vendor lock-in and hardware sales to make this a reality!

HP iLo Very Slow for Installing an OS

 

A bit of a disappointment; we’re trying to do a WinPE 2.0 CD/DVD based installation for our Windows 2003/2008 standard blade servers in an HP c7000 enclosure.

Installing from a .ISO image presented to the iLo via the virtual media applet is dog-slow (5-10 times slower than from a physical CD/DVD- why is this? – surely its technically possible to make this access run faster and GigE chipsets are cheap-as these days. I’ve been through every combination of switching/duplex/port config and even via a cable directly into the Blade OA.

The same issue seems to manifest itself on traditional rack mount HP servers – the iLo just isn’t fast enough to make this a workable solution, unless you are really patient.

I know we could use the RDP and do it as a PXE type installation over the network to each blade, but this doesn’t really achieve what I want…

Most customers maintain an OoB (Out of Band) network to which all of the management interfaces  (iLo, DRAC, etc.) are connected to. the reasoning for this is obvious; if you loose your main core switching network you can get access via a totally different physical network and path to assist in troubleshooting.

For this same reasoning I would like to use this method to build servers from a master boot CD/DVD image, you can present a .ISO image to a server via the virtual media applet on the iLo. We have a fully end-end build process that sets up the HP array controllers, flashes BIOS and installs the OS and drivers etc. from a CD/DVD.

We just update the boot CD .ISO file as required and its flexible and it doesn’t rely on any deployment infrastructure (PXE server, RDP server etc.) so we can port it between customers and data centres, VM’s and physical machines and do a bare-metal builds without requiring any build/network infrastructure in place.

This isn’t just limited to a Windows OS – I tried the same with an ESX installation; took over an hour (compared to 5-10 mins from a local CD)

Hot-Swap Datacentres

 

There’s an interesting post over on Forrester research blog by James Staten. he’s talking some more about data centres in a container; making the data centre the FRU rather than a server or server components (Disk, PSU etc.).

This isn’t a new idea but it I’m sure the economics of scale currently mean this is currently suitable for the computing super-powers (Google, Microsoft – MS are buying them now!) – variances in local power/comms cost could soon force companies to adopt this approach rather than be tied to a local/national utility company and their power/comms pricing.

But just think if you are a large out-sourcing type company you typically reserve, build and populate data centres based on customer load, now this load can be variable; customers come and go (as much as you would like to keep them long-term this is becoming a commodity market and customer’s demand you are able to react quickly to changes in THEIR business model – which is typically why they outsource – they make it YOUR problem to service their needs).

It would make sense if you could dynamically grow and shrink your compute/hosting facility based on customer demand in this space – thats not so easy to do with a physical location as you are tied to it in terms of power availability/cost and lease period.

New suite build out at a typical co-lo company can take 1-2 months to establish networking, racks, power distribution, cabling, operational procedures etc. (and that’s not including physical construction if it’s a new building) – adopting the blackbox approach could significantly reduce the start-up time and increase your operational flexibility

Rather than invest in in-suite structured cabling, rack and reusable (or dedicated) server/blade infrastructures why not just have terminated power, comms and cooling connections and plug them in as required within a secured warehouse like space.

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Photos from Sun Project Blackbox

You could even lease datacentre containers from a service provider/supplier to ensure there is no cap-ex investment required to host customers.

If your shiny new data centre is runs out of power then you could relocate it a lot easier (and cheaply) as it’s already transportable rather than tied to the physical building infrastructure; you are able to follow the cheapest power and comms – nationally or even globally.

As I’ve said before the more you virtualize the contents of your datacentre the less you care about what physical kit it runs on… you essentially reserve power from a flexible compute/storage/network “grid” – and that could be anything/anywhere.

VMWare ESX on IBM Blades

 

I’ve worked with HP c-class stuff recently, but this is a good article on the IBM equivalent and the post looks a lot simpler to read than all the official IBM docs!

In my book if you are virtualizing your infrastructure there is less of a religious argument on the underlying hardware – it’s a lot more flexible so do you care as much?

Thanks to Martins post on Bladewatch for the handy link

New Blade Blog

 

As Scott points out, Aaron has made a promising start with his new Blade focused blog*

Welcome, Aaron – I’ve already found something useful on your site and may need to rethink one of my blade deployment plans slightly!

*Edited 10/2/08 to update link for Aaron’s new URL