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Tuesday, 29 January 2013

Real World Fault Tolerance Use Cases

I've always been a big fan of VMware's Fault Tolerance feature but could never really find a valid use case to actually implement it.  Fault Tolerance (FT) has some very strict requirements / limitations:

  • VM is limited to one vCPU
  • VM disks need to be thick-eager zeroed
  • VM must be running a supported OS
  • Snaphosts are not supported on the VM (Think about how you can backup the VM)
  • VM Hot add memory or CPU cannot be utilised
  • DRS cannot be utilised
  • Physical processors needs to support FT

It is also recommended that you have a dedicated redundant FT network with minimum 1GB pNics for the FT traffic.  In our current infrastructure we are limited to the number of physical nics we can present to the ESXi hosts due to the blade chassis we are currently using.  We were unable to allocate 2 nics to dedicate to FT so we never really utilized FT.

We recently had a requirement to move our DMZ to our ISP and thus reused some decommissioned Dell R610 hosts.  We bumped up the memory and pNic count and now we could comfortably allocate 2 pNics per host for FT.  We use a Citrix Access Gateway (CAG) VPX appliance for remote access to both published apps and desktops and although this is protected with VMware HA, FT offered more protection in the event of a complete host outage.  The only issue that I had was that the CAG was not on the supported list of OS's but it seems to work fine.

We configured the hosts with the required FT network and enabled FT on the VM when it was powered off and 15 minutes later the VM was fully protected with FT


Wednesday, 16 January 2013

vSphere 5.1 Web Client US date locale

After recently upgrading my lab from 5.0 to 5.1 I was keen to start playing around with the new Web Interface Client since the thick GUI client might not be around for too much longer.  I'm not using the vCenter appliance so vCenter is installed on a Windows 2008 R2 server.  After stumbling through I noticed that when viewing tasks and events date format was showing US format of MM/DD/YYYY rather than the UK of DD/MM/YYYY:


Thinking this was simply that my windows locale was set to US I double checked but as expected it was showing correctly as United Kingdom.  This was for both the account that I was logged on as and the account the vCenter service was started with.  When checking the same events in the thick GUI client the format is showing correctly:


After a twitter conversation with Graham French the issue could be with a tomcat config file that could potentially be set to a US locale somewhere.  I've trawled both Google and the VMware KB site for anything referencing this and have so far came up with nothing.  I've checked as many config files as I can but just can't seem to find anything relating to this.  If anyone can shed any light on this I'd be much appreciated.

Update 18/01/2013

I spent countless hours looking through log files to try and find the default locale and then I suddenly remembered a KB article I read a while back about changing the language in the web client.  It then suddenly dawned on me that I should try the following:

https://<vCenterServer>:9443/vsphere-client/?locale=en_GB

hey presto:

Tuesday, 15 January 2013

North East VMUG – 07/02/2013

The next North East England VMUG will be held on Thursday 7th February from 12:30 onwards at:

Simpson Room, The CastleGate
Melbourne Street
Newcastle Upon Tyne
NE1 2JQ

Direction here

The agenda is as follows:

12:30 - Networking and Lunch
13:15 - VMUG Introduction
13:30 - Deep Dive and Demonstrations of VMware End User Computing Technologies Including Horizon, Octopus, HTML Remoting and Mirage - Peter Von Oven, VMware’s Lead UK EUC Specialist
14:45 - Refreshment and Networking Break
15:00 - Sponsor Presentation – Fusion-iO
15:45 - Refreshment and Networking Break
16:00 - Community Presentation – Upgrading from vSphere 4.1 to 5.1, Real World Experiences from the Field Graham French
16:45 - Raffle, Socrative, Other News
17:00 - Onwards – vBeers Sponsored by 10-Zig (Bridge Hotel)

Click here to register for the event

Big thanks to our sponsors Fusion-IO and 10Zig

         

Tuesday, 8 January 2013

Using Virtualization to migrate between two DMZ’s

We currently have a project ongoing to migrate away from an ASA5510 to two shiny new PaloAlto firewall’s which are located at out ISP.  This part of the project was to migrate all DMZ servers which currently reside on a single ESXi host onto a new DMZ cluster with shared storage at our ISP.  To make things a little complicated, not only were we migrating all our public internet facing services from one firewall to another, but also changing from one public IP address range to another all with minimal downtime.

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So, how did virtualization help with this?  Since all public facing servers were already virtualized (Aaprt from our Threat Management Gateway which will be by the end of the project) the actual migration of the VM’s from our current site up to our ISP was very easy using vMotion.  We simple stretched the VLAN up to our ISP and then migrated the servers over night via our 100mb link onto the new infrastructure.  Now this isn’t ideal as traffic was entering the ASA via another link, going across to our second site, going back to our ISP via another link and then hitting the server and then having to travel all the way back down to leave the ASA.  Since this was only a stop gap it was acceptable.  At the same time as stretching the VLAN across to our ISP we created another VLAN for the new DMZ and passed it through to both hosts.  So, both hosts up at our ISP could see the old VLAN hanging off the ASA and the new VLAN hanging of the PaloAlto firewalls.  We then verified and migrated the rule set from the ASA to the new PaloAlto devices and NAT’d the new public IP addresses to private IP addresses in the new VLAN for all the servers we were migrating.

This is where having these servers virtualized saved us potentially 24 to 48 hours downtime (Not including roll back).  We needed to find a way to test the NAT and security rules on the PaloAlto firewalls whilst minimising downtime on the VM’s as some of these servers run public facing websites.  We also needed to change the public IP address for these servers whilst maintaining connectivity.  Luckily all servers were simple web servers with static content.  We arranged downtime to clone each server and then power on the clone which was still connected to the old DMZ and who’s traffic flowed through the ASA.  Once the service was resumed via the clone we could change the network for the original server to be the new VLAN, who’s traffic flowed via the PaloAlto, re-ip it to fall in line with the new DMZ’s IP range and then test both internally and externally by changing the hosts file on our client pc’s to point the hostname to ether the public or private IP address.  This allowed us to test both the NAT and security rules whilst not interrupting any public facing services.  Once we were happy that the rule set was correct and signed off we simply contacted our ISP and requested them to change the public IP addresses for the hosts to point to the new addresses and within 24 to 48 hours users would start connecting to the original server rather than the clone.  After DNS had updated globally we could destroy the clone.  If all these servers were physical we would either have to look into migrating the services to virtual or another physical host which would involve significant work to build new servers and deploy applications or manually move them to our ISP, test firewall rules and then request the DNS changes which could have taken potentially a few days to fully complete and document.

Tuesday, 18 December 2012

VCAP5-DCA – My Experience

After passing my VCAP5-DCD exam at the second attempt it was naturally time to start revising for the VCAP5-DCA exam.  I booked the exam for Monday 3rd December at the Leeds Pearson VUE training center which is currently the closest testing point where I can sit the VCAP exam.  This is a bit annoying as it's a 2hr train journey there and back.  In preparing for the exam I used the following resources (In no particular order):

VCAP5-DCA Blueprint
Professional VMware vBrownBags
The Saffa Geek website
VlacoLabs website
Home Lab

This is the first time that I've sat the VCAP-DCA style exam which involved 26 questions in a lab environment accessed via a remote desktop connection.  I'm not going to explain how this exam is setup as there are plenty of posts out there, what I will explain is what issues I encountered whilst sitting the exam:

1.  The speed of the remote desktop session wasn't the greatest.  Opening and switching between applications was very laggy and when attempting to open the supplied .pdf documentation and scroll through was unusable.
2.  The supplied username and passwords were all identical but was there any need for the sheer complexity?  Due to the stress of the exam and time allowance I found it difficult to remember and had to constantly revert back to the screen which contained the details.  A nice and simple Administrator and vmware would have been preferred.
3.  When I actually started going through all the questions I noticed a few were already completed.  Without going into too much details certain tasks that I was being asked to completed seemed to already have been completed and only involved me checking over the results.  I first noticed this when being asked to save a .txt file in a certain location and the file already existed.  After a few more questions like this I raised it with the Pearson VUE test center who said they would log it with VMware and I should complete the exam.
Once I complete the exam I was informed that I would receive my results within 15 business days (Shourly there must be a quicker way to issues results in this day and age).

10 days later during a twitter conversation with Gregg Robertson, Matt Steiner picked up on the issues I experienced and raised it with a Senior Program Manager for technical certifications who asked me to provide feedback on my experience.  I fired off the mail informing him of the issues I encountered but they were unable to identify anything.  He kindly advised that I would get my results within the 15 business days as indicated but was nice enough to put me out of my misery and advised that I passed the exam.  A few days later my official results notification arrived in my inbox.

All in all I really enjoyed this style of exam and think a lot more should be delivered this way.  The speed of the session was an issue but nothing that you couldn't over come with a bit of patience.  I can now finally upgrade my lab from 5.0 U1 to 5.1 and enjoy and nice shiny new web interface.

Monday, 24 September 2012

North East VMUG #2

The next VMUG in the North East is taking place on Thursday 1st November from 12:30 – 17:00.  Matt Steiner from VMware has great little video about it:

http://www.xtranormal.com/watch/13669270/north-east-vmug-2-november-1st-2012

The agenda is based around Backup, Recovery and Storage and the location is:

The CastleGate
Melbourne Street
Newcastle
Tyne and Wear
NE1 2JQ

The full agenda is as follows:

12:30 - Registration and Networking Lunch. Enjoy some sandwiches and refreshments; meet today's sponsors Veeam and NetApp, your local VMware team and network with the VMUG committee and other members.
13:20 - Introduction from VMUG committee.
13:30 - VMware Presentation – A technical update from VMware's lead Business Continuity/DR consultant, Lee Dilworth who will provide a deep dive on vSphere Replication (now standard in vSphere), SRM 5.1 and vSphere Data Protection.
14:30 - Networking Break – Meet the sponsors and ask questions at the VMware genius bar.
14:45 - NetApp Presentation – A talk and demo around storage considerations for backup and DR.
15:15 - Veeam Presentation – A talk and demo around Veeam backup and recovery solutions.
15:45 - Networking Break – Meet the sponsors and ask questions at the VMware genius bar.
16:15 - vNews – An update with the latest news from Barcelona VMworld.
16:50 - Wrap up: An interactive Q & A session with the VMUG committee (bring your smartphone!) and raffle draw.
17:00 - Close and vBeers (Bridge Hotel)

If you need anymore information then feel free to reach out.

Saturday, 1 September 2012

RouterBOARD – Logging

The logging functionality within RouterBOARD is pretty impressive.  The log can be viewed from the main menu:
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In order to configure new logging you need to go into System –> Logging.  By default the following errors are logged:
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Logs can be sent to the following Actions (Locations):
Disk
When the disk option is selected then logs are stored on the local hard disk.  The local hard disk is around 61MB in size with around 31MB free (This can be viewed by going to System –> Resources).  You can amend the log to local hard disk options by clicking it and changing the required parameters:
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Echo
Not too sure what Echo is but I’m assuming it echo’s the log to the CLI.  Anyways, the following options can be changed for echo:
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Memory
Memory refers to the flash memory of the device.  This is roughly around 60MB with 45MB spare (This can be viewed by going to System –> Resources).  You can also change how many log lines are stored in memory to store more data:
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Remote
The final option is remote.  This refers to a remote syslog server where you can configure the IP address and port number:
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You can log a variety topics which include firewall, account, info, email, dhcp etc etc.  I wanted to log all firewall traffic that was being blocked.  To do this simply go back to the logging option and click the Red Plus sign under the Rules tab:
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In the Topic section add Firewall and then select where you want to log the data to.  In my case I’m just logging to memory.  You can also prefix some text to all firewall entries so you can easily identify it if you want.  Once finished simply click Apply:
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Your new rule to log firewall traffic should be visible:
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In order for the firewall to start logging traffic you need to add a firewall rule to tell it to log traffic.  To add the rule simply click IP –> Firewall and set focus to the Filter Rules tab.  By default there are 4 rules in place.  The first rule allows ICMP (Ping) traffic on all interfaces.  The second and third rules allow established and related traffic and the final rule blocks everything else:
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To add a log rule simply click on the red plus to add a new rule.  Click on the General tab and set the Chain to be forward and the In. Interface to be your external gateway (Where the internet is connected to):
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Click on the Action tab and set the Action to be Log and then also set a log prefix if you want and then click Apply
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The new rule should appear in the list of rules.  Simply drag the rule to where you want it to take affect.  If you want to see all traffic including allowed traffic then drag the rule to the top of the list.  If you only want to see dropped traffic then drag it just above the drop rule:
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To see if in action click on the Log button and you should dropped traffic starting to appear.