Monthly Archives: November 2015

c03601945

HP 2920 Switch – Reboot issue on firmware ver 15.18.0006 #vDM30in30

HP, Networking, , , , , , , , , , ,

Updated 25.11.15

Firmware WB.15.18.0007 resolves the issue, see below

A colleague of mine found an issue with the latest HP 2920 switch firmware.
If you create VLANs using the CLI Menu, the switch reboots and the configuration is not saved.

We have reported this to HP, but is currently being treated as a non critical issue as when creating a VLAN via the web interface or native CLI, the issue doesn’t happen.

We have also noticed on this firmware the switch seems to be less responsive. Luckily we had a few units in stock that we could replicate this issue on, and can confirm downgrading to the previous firmware version removes the issue.

A quick cheers to my colleague Marco for finding and researching this issue.

The issue

Switch: HP 2920-48G-POE+

Primary Image    :    12852982 08/12/15 WB.15.18.0006

Software revision  : WB.15.18.0006

  1.        Go to the Main Menu
  2.        Select (2) Switch Configuration…
  3.        Select (8) VLAN Menu…
  4.        Select (3) VLAN Port Assignment
  5.        Select Edit
  6.        Modify the tagging mode for a port
  7.        Select Save
  8.        Switch reboots and doesn’t save configuration

Hopefully HP will release a fix for this firmware soon, as mentioned we have recreated this issue in production and test.

The Fix

The following information was provided by HP Support. Continue reading HP 2920 Switch – Reboot issue on firmware ver 15.18.0006 #vDM30in30 →

backup error

Yet again, ESXi 6.0, CBT issues #vDM30in30

VMware, , , , ,

So here we are again, rounding the year off with yet another change block tracking warning.

I’ve written posts previously on the CBT bugs found in 5.5 and below and those found when vSphere 6.0 was released into the wild.

So whats the issue this time?

Basically it is the same as last time, the wrong sectors of data locations are returned by CBT when requested by your backup software. Meaning it targets the wrong data to backup.

Here is the official VMware KB 2136854. Which describes the following;

When running virtual machine backups which utilize Changed Block Tracking (CBT) in ESXi 6.0, you experience these symptoms:

 - The CBT API call QueryDiskChangedAreas() API call can sometimes      return incorrect changed sectors, which results in inconsistent  incremental virtual machine backups.

 - Inconsistent virtual machine backups

All incremental backups which utilize CBT are potentially affected.

Anton Gostev, Veeam, has released a lengthy email to Veeam customers and Gostev lovers stating the following (you can follow the veeam forum post here); Continue reading Yet again, ESXi 6.0, CBT issues #vDM30in30 →

citrix 580x224 tcm21 26525

Book Review – Citrix XenDesktop CookBook Third Edition – #vDM30in30

General, , , ,

So my second book review has been one I’ve looked to write for a while.

I had the chance to work with Citrix XenServer and XenDesktop in-depth as part of a virtualisation platform upgrade at a large educational establishment. Citrix is not my strong point, I’m more of a VMware person incase you hadn’t noticed.

This book was released as my project was coming to an end, after I had learnt the Citrix 7.6 product set from scratch, but I still thought it was worth a read. The author Gaspare A. Silvestri is a 10 plus year veteran with a heavy virtualisation background, and this isn’t his first Citrix Book!

Citrix XenDesktop Cookbook Third Edition Front Cover

The book itself jumps straight into how to install or upgrade an existing XenDesktop environment. It’s set out listing all the pre-reqs and then takes you step by step through the install process with screenshots as well. Continue reading Book Review – Citrix XenDesktop CookBook Third Edition – #vDM30in30 →

book review

Book Review – Countdown to Zero Day #vDM30in30

General, ,

After hearing about this book via twitter, and having an upcoming 8 hour flight plus holiday coming up, I decided to take a plunge into something a little different. Usually I’m more of a Stephen King fan or head buried into a technical book.

Countdown to Zero Day Front Cover

Stuxnet was one of the biggest developments in this side of the century, yet its creator remains faceless. Meaning its impact on the very devices we are using to read this blog post goes unnoticed in day-to-day life.

Kim has produced a book, which has far surpassed anything I’ve read in this category. Her writing style makes the information accessible to all technical levels, but the thing I enjoyed most was depth of research which split out of the pages to tell the story of the game changing malicious code, and choreographing this against the politic history of the West vs the Middle East.

Continue reading Book Review – Countdown to Zero Day #vDM30in30 →

ccnp datacenter large

Exam Experience – Cisco CCNP Datacenter – 642-998 Designing Cisco Data Center Unified Computing (DCUCD) – #vDM30in30

Cisco, General, , , , , , ,

Evening,

Sorry for the long title.

There is two reasons as to why you would be taking this exam. The first is because you want to achieve the CCNP Datacenter title, or the second is because your company requires you to, so they can achieve the Unified Computing Technology Specialization.

My reason was the second, but the Cisco Datacenter track is something I am interested in in the long run.

If your going for the partner route like me, you are not required to have the CCNA DC under your belt. But if you want to achieve the CCNP DC, you need to complete the correct pre-reqs, which can be found here.

The exam is 90 minutes with around 70 questions. The recommendation is to undertake the Designing Cisco Data Center Unified Computing course from an authorised Cisco Learning Partner. Which is exactly what I did, and then sat the exam straight after.

I will blog about the course separately.

spongebob-exam

Exam Experience

So the exam was the usual Cisco, its made of majority multiple choice questions, and I also had two small testlets.

Continue reading Exam Experience – Cisco CCNP Datacenter – 642-998 Designing Cisco Data Center Unified Computing (DCUCD) – #vDM30in30 →