1. Dell Bkb Netvault Bu Standard Edition Upgrade 2tb Virtual Library
2. Dell Bkb Netvault Bu Standard Edition Upgrade2tb Virtual Library

April 24, 2017 by What is VMware Changed Block Tracking and How It Works When thinking about modern, most leverage a technology called Changed Block Tracking or CBT to facilitate taking incremental backups of virtual machines. This technology is derived from the VMware Data Protection API which allows third-party backup applications to take advantage of CBT to perform backups. The advantage of VMware CBT is that it significantly reduces the amount of time the backup software takes to perform incremental backups because it tracks changes in a special Changed Block Tracking log file. VMware Changed Block Tracking not only benefits incremental backups but also all related activities such as. Changed Block Tracking is also used by VMware’s Storage vMotion process that allows virtual machine disk files to be moved from one datastore to another while it is running. Let’s take a closer look at how Changed Block Tracking works, requirements for CBT, how to enable it, and how it relates to third-party backup utilities. How VMware Changed Block Tracking Works?

Changed Block Tracking technology actually keeps up with the blocks of a virtual machine disk that have changed since a certain point in time like a checkpoint. There are obvious advantages when thinking about changed block tracking when it comes to backup operations as mentioned earlier. So, let’s see how CBT technology works.

Dell Bkb Netvault Bu Standard Edition Upgrade 2tb Virtual Library

VMware CBT technology is a part of the VMkernel storage stack that is available for third party applications to query via the vStorage APIs for Data protection. Changed Block Tracking is a VMFS filter.

Dell Bkb Netvault Bu Standard Edition Upgrade2tb Virtual Library

Requirements for Changed Block Tracking include:. vSphere.

Version 7 virtual hardware or higher. NFS or iSCSI datastores. Thick or thin provisioning. No RAW disk mappings What are the “blocks” that are recorded that are changed? Changed Blocks are recorded at a VMDK level and not a VMFS level and the variable block sizes are dictated by the size of the VMDK represented. Changed Block Tracking is enabled in a virtual machine’s advanced configuration parameters.

This can be added by navigating to the Advanced/General Configuration Parameters configuration of the virtual machine. CBT activation is determined by the line ctkEnabled = “True” line in the VMX configuration. Also, for each disk that CBT is enabled, an entry will be included:. scsix:x.ctkEnabled = “TRUE” Once CBT is enabled on a virtual machine, the VMkernel creates an additional file with “-ctk.vmdk” in the virtual machine directory that is used to store the mapping of virtual disk blocks. Inside this “ctk” file are sequence numbers that can tell if the blocks for a specific virtual machine disk have changed. The size of the “ctk” file that gets created stays the same and does not grow beyond the original size unless the size of the virtual disk is increased. The size of the “ctk” file is approximately.5MB for every 10GB of the virtual machine disk size.

Most backup solutions will use the VMware SDK method to programmatically enable CBT for a virtual machine and use a stun/unstun cycle which includes either power on or off, suspend/resume, or create/delete a snapshot. During a stun/unstun cycle a special change tracking filter is inserted into the VMware storage stack for the particular VM which allows changed block tracking to instantiate on the virtual machine. Thoughts VMware Changed Block Tracking is an integral part of modern solutions providing efficient backups of today’s production VMware environments. The built-in VMware APIs allow for hooks into this technology to be utilized for both backup and replication processes.

The technology is well tested and heavily utilized not only in backup solutions but also in tried and true VMware technology such as Storage vMotion.

Forex factory calendar downloader for mac. While verbose, try running this command which should be equivalent to what certbot-auto is trying to do at this step: virtualenv -no-site-packages -python $(command -v python2.7 command -v python27 command -v python2 command -v python) $(mktemp -d) If that works, I recommend deleting /.local/share/letsencrypt and trying again. If it doesn't work, it suggests a problem with virtualenv or maybe the Python found at $(command -v python2.7 command -v python27 command -v python2 command -v python).

: Thank you for your suggestions, I tried them. 'virtualenv -no-site-packages -python $(command -v python2.7 command -v python27 command -v python -vvvvv' worked well. I deleted '/.local/share/letsencrypt' that was owned by root, then run 'sudo./certbot-auto' again. I noticed this warnings: 'The directory '/home/myhome/.cache/pip/http' or its parent directory is not owned by the current user and the cache has been disabled. Please check the permissions and owner of that directory.

If executing pip with sudo, you may want sudo's -H flag. The directory '/home/myhome/.cache/pip' or its parent directory is not owned by the current user and caching wheels has been disabled. Check the permissions and owner of that directory. If executing pip with sudo, you may want sudo's -H flag.' . As next steps, I deleted /.local/share/letsencrypt/, /.cache/pip/, and also /root/.local/share/letsencrypt/ and /root/.cache/pip/. Then I ran 'sudo -u myusername -H /net/letsencrypt/bin/certbot-auto'.

It installed cerbot-auto again, created /.local/share/letsencrypt/ and /.cache/pip/ with myusername as owner, without problem, without warning. However, '/net/letsencrypt/bin/certbot-auto' alone still complains: 'Creating virtual environment.

ImportError: No module named site'. When executed the original 'certbot-auto -v' again, I got now these error messages: 'ERROR: The executable /home/myhome/net/letsencrypt/bin/:/usr/local/monodevelop-3.0.3.5/share/letsencrypt/bin/python2.7 is not functioning ERROR: It thinks sys.prefix is u'/home/myhome/net/letsencrypt/bin' (should be u'/home/myhome/net/letsencrypt/bin/:/usr/local/monodevelop-3.0.3.5/share/letsencrypt') ERROR: virtualenv is not compatible with this system or executable' Then I deleted all letsencrypt folders, and got the same errors. It seems virtualenv conflicts with mono on my computer.

Then I went to a virtual machine, also with Ubuntu 14.04, and installed certbot-auto there, without problems. How can I delete / rebuild the virtualenv? The virtual environment created by certbot-auto is in /.local/share/letsencrypt so I believe you've deleted that multiple times.

As for the actual virtualenv executable, certbot-auto installs one through apt but it's possible you have another one on your system (from something like pip). Is there a difference in the output of which virtualenv, running the command once with root and once without? If not, you can try reinstalling the package from apt. Two more questions:. Following the instructions I wrote, where does that error occur?. What's the value of PATH before calling the script.

Thanks again for the suggestions. As virtualenv and PATH had produced the same output with and without 'sudo -u hanak', I uninstalled virtualenv by pip and purged python-virtualenv by aptitude (apt-get). Then I ran './certbot-auto -no-self-upgrade -verbose' that failed in the well-known error, and then 'sudo -u hanak./certbot-auto -no-self-upgrade -verbose' that succeeded.

I have noticed a slight difference at the end of the outputs. This was produced with 'sudo -u.' : python-virtualenv is already the newest version. 0 upgraded, 0 newly installed, 0 to remove and 5 not upgraded. Creating virtual environment. Running virtualenv with interpreter /usr/bin/python2.7 New python executable in /home/hanak/.local/share/letsencrypt/bin/python2.7 Also creating executable in /home/hanak/.local/share/letsencrypt/bin/python Installing setuptools, pip.done.

Installing Python packages. Installation succeeded.

And this without 'sudo -u.' : python-virtualenv is already the newest version. 0 upgraded, 0 newly installed, 0 to remove and 5 not upgraded. Creating virtual environment.