Category Archives: VMware

Further ESXi 6.0 CBT bug info – Reset your CBT!!!

Following on from the recent (November 2015) ESXi 6.0 CBT bug, which has now been fixed in the latest released patch ESXi600-201511401-BG, some further information has come to light, provided by Anton Gostev, of Veeam.

You can read the snippet of important information from the Veeam forum post following the issue (Official Veeam KB2075);

All, we have completed the first day of testing in the same exact lab and using the same heavy write I/O test that made the original issue easily reproducible. After a few TB of increments, the above-mention patch appears to fully resolve the original issue when installed on ESX 6.0 Update 1a build 3073146.

However, we found that simply installing the patch is not sufficient, and CBT reset is required for all of your VMs. This is because existing CBT map files may contain issues created earlier due to the original bug, which may result in inconsistent full backups in future. Having CBT reset will also force the following job run use "full scan" incremental pass, thus fixing any existing inconsistencies in backups and replicas, as discussed earlier in this topic.

Provided CBT reset has been performed, Active Full backups is not required.

Performing Active Full backups by itself cannot be considered as a substitute to CBT reset with this particular CBT issue.

Thanks!

You can either follow the CBT Reset instructions from Veeam or look over to Chris Wahl’s latest blog post “Resetting VMware’s Changed Block Tracking (CBT) File with PowerCLI”.

Regards

Dean

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Exam Experience – VMware VCP6-DT #vDM30in30

Today I took the VCP6-DT exam. It will be retired on 30th November 2015. And is replaced by the VCP6-DTM exam, as part of the VMware exam overhaul.

So why take an expiring exam?

Well VMware is kindly going to upgrade it to the VCP6-DTM anyway.

2015-11-26_21-31-47

I’ve spent a number of years as a VMware customer running a large VDI deployment, from administration to re-architecture of the environment. I never took the exam due to a number of reasons. One being the course requirement, and the fact my employer would not send me on a £2500+ training course. Since then I’ve done my VCP6-NV and my VCP5-DCV, so slowly I’ve chiselled away at going through the topics and preparing myself for the VCP6-DT, so with them offering to upgrade it, and the fact I don’t really touch some of the newer products (app volumes, air watch etc). I decided to stick with the VCP6-DT.

So whats the difference between the VCP6-DT and VCP6-DTM?

Continue reading Exam Experience – VMware VCP6-DT #vDM30in30

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ESXi 6.0 CBT Issue KB 2136854 – Resolved #vDM30in30

I wrote about the latest CBT issue (November edition) a couple of days ago, and as promised by VMware a patch has been released.

Original issue – KB 2136854

Patch to resolve the issue – ESXi600-201511001 (2137545)

Note: Before applying this patch on HP Proliant Gen 9 servers, see VMware ESXi 6.0 host fails to detect local disk after patching or applying Update 1 on HP Proliant Gen 9 servers (2120539).

103112_Solve_5_Major_Issues

Cheers VMware, lets hope this is the last of the CBT issues!!!
Regards

Dean

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Yet again, ESXi 6.0, CBT issues #vDM30in30

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

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And more blogs and sites I’ve been reading and sharing

A little bit of a longer one than usual, as I was part way through writing this the other month, then I got distracted with other blog posts.

Hope you find some of these useful.

Documentation

EtherealMinds Eleven Rules of Design Documentation – This is one the best articles I’ve read in a long time, and reiterates the fact you need to keep it simple and a diagram replaces a thousand words.

Microsoft Continue reading And more blogs and sites I’ve been reading and sharing

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