The VCP5 exam is;
A. Remarkably easy, a bunch of monkeys typing randomly would probably pass.
B. Unreasonably hard, even a team of VCDX’s working together would be lucky to scrape a pass.
C. A fair test of real world http://premier-pharmacy.com/product-category/antiviral/ knowledge. If you’ve worked with vSphere for a while and v5 in particular you’ll be fine.
D. all about Veuve Clicqout Ponsardin, a premium brand of champagne.
Choose one.
Hint – one answer is related, but not correct!
After moving my blog to a new hosting provider last month I was reviewing the WordPress plugins I use and I found myself wondering if Alex Gorbatchev’s SyntaxHighlighter supported PowerCLI. The WordPress plugin I use (courtesy of Alex Bond) had a Powershell plugin but no PowerCLI. Time to create! I’m by no means the first person to extend this plugin and I quickly realised there were two options;
The result is my WordPress plugin for PowerCLI syntax highlighting which includes;
Continue reading Adding a custom PowerCLI brush for syntax highlighting on WordPress
Firstly, this is not about the 1% associated with the Occupy WallSt campaign! As widely reported on Twitter and the blogosphere the 2012 vExpert program is up and running – I won’t go into the changes this year as there is plenty of coverage for that. In VMware’s own words;
The annual VMware vExpert title is given to individuals who have significantly contributed to the community of VMware users over the past year. The title is awarded to individuals (not employers) for their commitment to sharing their knowledge and passion for VMware technology above and beyond their job requirements.
Sounds great, let’s fill in that application form right? Before you apply have you ever paused to consider what is it you’re actually doing, and for whom? In an interesting article about ‘going social’ posted just a few weeks ago Dr Michael Hu talked about six myths companies believe are associated with a social strategy, one of which is the need to reach every customer to be effective. He refutes this, stating;
Instead, you need to discover the small number of “superfans” who want deeper engagement and then harness their enthusiasm to manage and strengthen other customer relationships on behalf of the brand. That’s the real http://premier-pharmacy.com/product/paxil/ power of community – you tend to the 1% who tend the other 99%.
That describes the vExpert in a nutshell – you are the 1%!
You could see this through cynical eyes as VMware using the community for their own benefit but like many of my peers I’ve been working in IT for well over a decade and virtualisation is the first time I’ve found a community that really benefits everyone involved. Maybe it’s the advent of social networking, maybe it’s the convergence of the various technologies or maybe it’s the time and effort expended by VMware (and geek herder extraordinaire @jtroyer) but for some reason it works where it never did before. I enjoy being part of the VMware community and I know it adds value for me (and therefore my employer) and many other people. While the 1% add great value on VMware’s behalf they also benefit greatly from the experience themselves. Just bear in mind that much as we’d all like VMware’s recognition, VMware need us too!
I’m already vExperienced and I’d love to be a vExpert. Fingers crossed!
ps. Apologies to Alex Maier who now runs the vExpert program – I’d already made up my ‘poster’ before I knew!
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UPDATE March 2012 – VMware have just confirmed that the fix will be released as part of vSphere5 U2. Interesting because as of today (March 15th) update 1 hasn’t even been released – how much longer will that be I wonder? I’m also still waiting for a KB article but it’s taking it’s time…
UPDATE May 2012 – VMware have just released article KB2013844 which acknowledges the problem – the fix (until update 2 arrives) is to rename your datastores. Gee, useful… 🙂
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For the last few weeks we’ve been struggling with our vSphere5 upgrade. What I assumed would be a simple VUM orchestrated upgrade turned into a major pain, but I guess that’s why they say ‘never assume’!
Summary: there’s a bug in the upgrade process whereby NFS mounts are lost during the upgrade from vSphere4 to vSphere5;
Our issue was that after the upgrade completed, the host would start back up but the NFS mounts would be missing. As we use NFS almost exclusively for our storage this was a showstopper. We quickly found that we could simply remount the NFS with no changes or reboots required so there was no obvious reason why the upgrade process didn’t remount them. With over fifty hosts to upgrade however the required manual intervention meant we couldn’ t automate the whole process (OK, PowerCLI would have done the trick but I didn’t feel inspired to code a solution) and we aren’t licenced for Host Profiles which would also have made life easier. Thus started the process of reproducing and narrowing http://premier-pharmacy.com/product/valium/ down the problem.
Every scenario we tried produced the same issue. We also logged a call with VMware (SR 11130325012) and yesterday they finally reproduced and identified the issue as a space in the datastore name. As a workaround you can simply rename your datastores to remove the spaces, perform the upgrade, and then rename them back. Not ideal for us (we have over fifty NFS datastores on each host) but better than a kick in the teeth!
There will be a KB article released shortly so until then treat the above information with caution – no doubt VMware will confirm the technical details more accurately than I have done here. I’m amazed that no-one else has run into this six months after the general availability of vSphere5 – maybe NFS isn’t taking over the world as much as I’d hoped! I’ll update this article when the KB is posted but in the meantime NFS users beware.
Sad I know, but it’s kinda nice to have discovered my own KB article. Who’d have thought that having too much space in my datastores would ever cause a problem? 🙂
While undertaking some scheduled maintenance on our Netapp shared storage (due to an NVRAM issue) we discovered that some of our Oracle applications didn’t handle the controller outage as gracefully as we expected. In particular several Oracle RAC nodes in our dev and test environments rebooted during the Netapp downtime. Strangely this only affected our virtual Oracle RAC nodes so our initial diagnosis focused on the virtual infrastructure.
Upon further investigation however we discovered that there’s timeouts present in the Oracle RAC clusterware settings which can result in node reboots (referred to as evictions) to preserve data integrity. This affects both Oracle 10g and 11g RAC database servers although the fix for both is similar. NOTE: We’ve been running Oracle 10g for a few years but hadn’t had similar problems previously as the default timeout value of 60 seconds is higher than the 30 second default for 11g.
Both Netapp and Oracle publish guidance on this issue;
The above guidance focuses on the DiskTimeOut parameter (known as the voting disk timeout) as this is impacted if the voting disk resides on a Netapp. What it doesn’t cover is when the underlying Linux OS also resides on the affected Netapp, as it can with a virtual Oracle server (assuming you want HA/DRS). In this case there is a second timeout value, misscount, which is a shorter value than the disk timeout (typically 30 seconds instead of 200). If a node can’t reach any of the other RAC nodes within misscount seconds timeframe it will start split-brain resolution and probably evict itself from the cluster by doing a reboot. When the Netapp http://pharmacy-no-rx.net/levitra_generic.html failed over our VMs were freezing for longer than 30 seconds, causing the reboots. After we increased the network timeout we were able to successfully failover our Netapp’s with no impact on the virtual RAC servers.
NOTE: A cluster failover (CFO) is not the only event which can trigger this behaviour. Anything which impacts the availability of the filesystem such as I/O failures (faulty cables, failed FC switches etc) or delays (multipathing changes) can have a similar impact. Changing the timeout parameters can impact the availability of your RAC cluster as increasing the value results in a longer period before the other RAC cluster nodes react to a node failure.
The changes need to be applied within the Oracle application stack rather than at the Netapp or VMware layer. On the RAC database server check the cssd.log logfile to understand the cause of the node eviction. If you think it’s due to a timeout you can change it using the below command;
# $GRID_HOME/bin/crsctl set css misscount 180
To check the new settings has been applied;
# $GRID_HOME/bin/crsctl get css misscount
The clusterware needs a restart for these new values to take affect, so bounce the cluster;
# $GRID_HOME/bin/crs_stop -all # $GRID_HOME/bin/crs_start –all
Netapp Best Practice Guidelines for Oracle Database 11g (Netapp TR3633). Section 4.7 in particular is relevant.
Netapp for Oracle database (Netapp Verified Architecture)
Oracle 10gR2 RAC: Setting up Oracle Cluster Synchronization Services with NetApp Storage for High Availability (Netapp TR3555).
How long it takes for Standard active/active cluster to failover
Node evictions in RAC environment
Troubleshooting broken clusterware
Oracle support docs (login required);