Reclaiming disk space from thin provisioned VMDK files on ESXi (2136514)

-

 Reclaiming disk space from thin provisioned VMDK files on ESXi (2136514)


https://kb.vmware.com/s/article/2136514


Symptoms

Virtual Machines (VM) using thin provisioned disk do not see size decrease after deleting files from the Guest Operating System.
 

Purpose

This article provides steps to manually reclaim unused disk space by the Guest OS to shrink the thin provisioned disk. For more information, see Storage Space Reclamation.

Cause

Deleting data from Guest OS only removes the data from the file allocation table but does not zero the blocks. As a result, the ESXi Host still sees the blocks in use even after deleting the data.

Resolution

Note: Reclaiming disk space only works when the blocks on your virtual disk are not in use by the Guest OS. 

Reclaiming disk space is a two steps process

The first step is to delete the blocks on the Guest Operating System then reclaim space on the VMFS datastore. Be sure to follow the bellow steps in order.

Step 1: Delete the blocks on the Guest OS

Windows Operating System

  1. Download SDelete Command Line Tool available at https://docs.microsoft.com/en-us/sysinternals/downloads/sdelete
Note: SDelete -z will cause the guest OS to use up 100% of the available space disk during this process while zeroing free space. This will lead to a temporary increase in used space on the datastore.

  1. Open an elevated command prompt.
  2. Run this command
sdelete.exe -z drive_letter:
 

Note: Replace [drive:] with the target disk or partition. Note that when you have multiple partitions on a single virtual disk, you need to do this on all partitions for it to be effective. Otherwise, reclamation will only be partial because not every data block will be zeroed.

Linux Operating Systems:


Linux has different ways to delete the unused blocks, the most common method is to fill the free space with a file of zeroes using the dd command:

 

$ dd if=/dev/zero of=/mounted-volume/zeroes && rm -f /mounted-volume/zeroes


​​​​​Notes:

  • Be sure to shutdown all services which writes to the target volume to avoid running out of space
  • If there are multiple partitions on a single virtual disk, same step needs to be performed on all partitions. Otherwise the reclamation will be partial because not every data block will be zeroed.

Step 2: Reclaim space on VMFS

  1. Power off the virtual machine.
  2. Log in to the ESXi host using SSH and root credentials.
  3. Navigate to the directory that contains the virtual machine disk using the command:
cd /vmfs/volumes/DATASTORE_NAME/VM_NAME

  1. Run this command:
vmkfstools -K disk_name.vmdk

Notes: 

  • The file used here is descriptor file .vmdk file not the data file -flat.vmdk
  • The process may take longer depending on the size of the disk and number of blocks.

Comments

Post a Comment

Popular posts from this blog

Extracting and using a modified VMWare Player BIOS or UEFI firmware

-
https://pete.akeo.ie/2011/06/extracting-and-using-modified-vmware.html Extracting and using a modified VMWare Player BIOS or UEFI firmware (updated 2016.05.17 for VMWare UEFI firmware extraction) One day or another, you may want to play with BIOS/UEFI firmware modification. But before jumping into physical motherboard flash alteration, where the consequences of a mishap can be difficult to salvage, experimenting with the BIOS/UEFI in a virtual environment sounds like a sound first step. You have of course the opportunity to do so using  bochs , however the ubiquitous nature and ease of use of the (freely available)  VMware Player  can turn the latter in a much better candidate for the job if you don't really care about the extra features that bochs brings in. This post details how one can extract the BIOS/UEFI firmwares used by the VMWare Player, and how to setup the player to use a modified one. Download and install VMware Player. The current version of VMwar...
Read more

Activate Synology Active Backup for Business for DSM 6

-
 Activate Synology Active Backup for Business with Xpenology DSM  https://gist.github.com/igresc/91e468f3d2ad5f2f7407262ba6f0dd56 Install the package and run the URL below on the browser . Active Backup for Business 1. Replace the IP, username, and password  http:// 192.168.0.1 :5000/webapi/auth.cgi?api=SYNO.API.Auth&method=Login&version=1&account= admin &passwd= password {"success":true} 2. Replace IP and Serial http:// 192.168.0.1 :5000/webapi/entry.cgi?api=SYNO.ActiveBackup.Activation&method=set&version=1&activated=true&serial_number= 1780PDN123456 {"data":{"activated":true},"success":true} Active Backup for G Suite 1. Replace IP http:// 192.168.0.1 :5000/webapi/entry.cgi?api=SYNO.ActiveBackupGSuite&method=get_activation&version=1 {"data":{"activated":false,"serial_number":"1780PDN123456"},"success":true} 2. Replace IP and Serial 1. Replace IP http:// 19...
Read more

Windows 11 internet/account bypass

-
Image
https://github.com/the-P1neapple/WinJS-Microsoft-Account-Bypass WinJS-Microsoft-Account-Bypass Overview This guide explains a method to bypass the Microsoft Account (MSA) requirement during the Windows 11 Out-Of-Box Experience (OOBE) by using the Developer Console to invoke a hidden local account setup screen. This method was discovered by examining the Windows 11 OOBE source code, which revealed an event listener for a hidden  _localAccountButton . Note A faster method has since been discovered using Command Prompt ( Source ), this repo was made 7 months prior to that discovery. The method I have documented is still the only known method for S-Mode installations. Following these steps, you can create a local account without needing to sign in with or create a Microsoft account. I also have a  Youtube Tutorial  that follows the same instructions below Steps to Bypass Microsoft Account Setup 1. Start Windows 11 Setup Begin the Windows 11 Setup Process. Select your region a...
Read more