1 April 2022

Bitnami Start or Stop Services

I found a great Bitnami Docs KB article describing how to check the status of, and stop/start/restart the services running on your Bitnami instance.

Each Bitnami stack includes a control script that lets you easily check the status of, stop, start and restart services.

These are the commands that you would use. If you use them as-is below it will perform the specified action against all the Bitnami services on your instance.

sudo /opt/bitnami/ctlscript.sh status
sudo /opt/bitnami/ctlscript.sh start
sudo /opt/bitnami/ctlscript.sh stop
sudo /opt/bitnami/ctlscript.sh restart

Or use any of the above against a single service that is running, such as Apache only, by passing the service’s name as an argument after the desired action, such as restart.

sudo /opt/bitnami/ctlscript.sh restart apache

The easiest way to learn the names of the services that are on your Bitnami instance is by simply checking all of their statuses with the status command as it returns the names of all the services on your instance.

sudo /opt/bitnami/ctlscript.sh status
Category: Bitnami, Linux, WordPress | LEAVE A COMMENT
31 March 2022

ESXi Access to resource settings on the host is restricted

I was trying to upload an ova file thru vCenter when I got an error message about a controller type in this particular ova. From prior troubleshooting, I knew that the workaround was to just log directly onto a host and upload the ova directly to the host. I know I had done this before so I was confused for a brief moment when I got the error message:

Access to resource settings on the host is restricted to the server that is managing it: xx.xx.xx.xx.

Okay… so the ESXi host is being managed by vCenter. How do I finagle my upload onto a host? Here’s how…

  • Enable SSH (if it is disabled) on the ESXi host you want to upload/deploy your ova or ovf to.
    • You should know how/where to enable SSH… If you don’t there are plenty of articles you can google.
  • Connect to the host via SSH.
  • We want to stop the service that allows the ESXi host and the vCenter to communicate. To do so we want to run the following commands.

/etc/init.d/vpxa stop
/etc/init.d/hostd restart

  • Deploy your ova or ovf to your host thru the ESXi host’s DCUI WebGUI.
  • After you deploy your virtual machine, restart the VPXA service via SSH on the ESXi host.

/etc/init.d/vpxa start

  • Wait a couple of minutes while the ESXi host and your vCenter re-establish communication between each other.
  • If SSH was previously disabled, re-disable it on your host.
Category: ESXi, vCenter, VMWare | LEAVE A COMMENT
27 March 2022

Monitor Desk Mount

After getting a new desk you need to get some hardware to finish dialing it in how you want. For me, after getting a new desk at home, one of those things that I needed was a way to mount my monitor. I spent more hours reading through product reviews than I’d like to admit, but the end result was something I’m happy with.

So heading into my search I had a few things in mind. First, I’m not against purchasing expensive items if their value is worth it. That said, I did not want to go spending a few hundred dollars on a new mount. I felt like there were so many Chinese knockoffs on the Amazon alone that I could surely find a good deal on something of middle-of-the-road quality. Ideally, I wanted to spend under $100 on it. The second thing I really wanted was a mount that would fit dual monitors The plan was to search for a dual monitor stand so I could have two screens running. The third thing I was looking for was for it to be a clamp-on style mount. Having a child in my house I wanted something that would be secured to the desk. Something that I wouldn’t have to worry about being top-heavy and toppling over if the little one was screwing around and “bumped” the desk too hard.

So now that I laid out my wants, how did I do, and what did I decide to get?

After reading a ton of reviews I decided to shift from a dual monitor to a single monitor stand. Having two individual arms would allow me better flexibility on the screen size. With my current monitors being two different sizes (32″ and 21″) this makes things easy and in the future, I don’t ever have to worry about the monitor size as a limitation.

I had lots of clamp-style mounts to choose from on Amazon. It ended up being pretty easy to find one that I liked. However, one thing that I hadn’t originally considered getting was a reinforcement bracket for the clamp. It helps to distribute the pressure from the mount’s clamp and protects the desk from stress fractures over time. It’s basically just a small steel plate that sits between the desk and the clamp. After looking at my desk and giving it some thought, I figured it’d be worth the few extra bucks it cost.

My final purchase was a fully articulating arm for up to a 32″ monitor. I spent $32.99 on it and I feel like I got a good deal on it considering how high some of the arms can cost. The one I purchased was the MountUp Single Monitor Desk Mount.

I paired that with the WALI Steel Reinforcement Bracket for $16.99

And because nothing can ever go smoothly, the VESA mount holes on the arm and one of my monitors were different sizes. So I ended up getting the Husky Mounts VESA adaptor for it for $10.95. It solved my issue no problem.

So I managed to get a solution that works for me all for $50 per monitor (not including the VESA adaptor). I think that I did alright getting everything I wanted for $100.

What sort of monitor stand or mount do you use?

Category: Gadgets | LEAVE A COMMENT
24 February 2022

Changing Your Password from an RDP Session

So here’s the scenario, you’ve RDP-ed into a server and you want to change your password. You try to hit CRTL+ATL+DEL but instead of it getting sent to the remote computer, it opens on your local machine. Blah! That is not what we want… How do we get to a place where we can change the password for the account that was used in the RDP session?

One way to send it within the RDP session is to launch the on-screen keyboard. To launch it, simply click on the ‘Start Menu’ and type “osk”, then click on the result to open the keyboard. With the OSK on screen, press and hold “CTRL+ALT” on your physical keyboard, and click “DEL” on the virtual keyboard button.

The easiest way to bring up the menu from where you can change your password is to press CRTL+ALT+END in the RDP window. Now if you are RDP-ed from a mac, you’ll need to do a CRTL+ALT+Fn+Backspace or CRTL+ALT+Fn+Right-Arrow to bring up the menu.

Category: Microsoft, Windows 10, Windows 2016, Windows 2019 | LEAVE A COMMENT
2 February 2022

vMotion Greyed Out

Okay… This was a first for me. I was in VCSA and went to vMotion a VM, a totally normal task. However, upon clicking on the VM and trying to run the vMotion, it option was greyed out. WHAT THE HECK!?!
Well, thankfully it ended up being a simple fix. Apparently, this can happen if the VCSA database does not get properly updated after a backup job. Here’s how to re-enable it.

Manually remove entries from the vCenter Mob:

  1. Identify the VM’s MOB ID
    1. Open a web browser and go to the vCenter vSphere Client (HTML5)
    2. In the left hand side inventory, select the affected VM’s object
    3. With the VM selected and highlighted, in the URL bar, review the string and look for “VirtualMachine:vm-xx“

Example: https://<VCSA-FQDN>/ui/#?extensionId=vsphere.core.vm.summary&objectId=urn:vmomi:VirtualMachine:vm-69:7071ab73-c123-4d56-ef78-1234gh56i7jk&navigator=vsphere.core.viTree.hostsAndClustersView

In this example VM’s MOB ID is vm-69.

  1. ​​​​​​Access the Virtual Machine Operations by opening a web browser to: 

https://<VCSA-FQDN>/mob/?moid=AuthorizationManager&method=enableMethods

  1. Login with administrator@yourssodomain.local or an SSO admin user (administrator@vsphere.local)
  2. The below page will appear:
  1. In the first parameter entity value box, replace MOID with the VM’s MOB ID

<!– array start –>
<entity type=”ManagedEntity” xsi:type=”ManagedObjectReference”>vm-69</entity>
<!– array end –>

  1. In the second parameter entity value box, enter this command:

<method>RelocateVM_Task</method>

  1. Click on “Invoke Method” in the lower right corner.
  1. Refresh the vCenter Server web client and the migration option for the VM should now be available. If the issue persists, try restarting all of the vCenter Server services.

Here is VMware’s KB about it.

Category: vCenter, VMWare | LEAVE A COMMENT
28 January 2022

Nutanix LCM – Insufficient space on ESXi scratch disk

I was running into an issue where I could not run the Nutanix LCM Inventory action on a cluster because the scratch disk on an ESXi host was too small. And it seems reasonable to assume that if you’re reading this article, then you too probably have encountered an with the pre-check “test_esxi_scratch_space“.

I’ve seen the issue a few times now, and in my experience, the ESXi host has always just had its scratch disk set to the wrong disk. The first couple of times I saw this, the fix was to update the scratch disk from within the advanced host settings in VCSA. The part I did not like about fixing the issue this way, was that it required a reboot of the host for the setting to take hold. Having to schedule a maintenance period or create downtime is never an ideal solution. Thankfully I learned that there is another way to repoint the scratch disk that requires no downtime and it only requires a few lines of CLI against the ‘problem’ ESXi host.

Start by connecting via SSH to the ESXi host that is having the issue with the scratch disk.

Run the command “ls -ll /scratch” to find which volume is currently set as the scratch disk

root@ESXi# ls -ll /scratch
lrwxrwxrwx    1 root     root            49 May  8 23:40 /scratch -> /vmfs/volumes/5xyzxyz6-dxyzxyzb-1c73-ac1xyzxyz990

Run the “df -h” command to list all of the disks on the host and their sizes

root@ESXi# df -h

Filesystem   Size   Used Available Use% Mounted on
NFS          1.6T   1.4T    127.4G  92% /vmfs/volumes/OS-XXX-Repoxxx
VMFS-5      52.0G   1.1G     50.9G   2% /vmfs/volumes/NTNX-local-ds-17xyzz340111-B
vfat         4.0G  27.6M      4.0G   1% /vmfs/volumes/5xyzxyz-1234xyzz-12xy-1234xyzz1234
vfat       285.8M 205.8M     80.0M  72% /vmfs/volumes/5xyzxyz6-dxyzxyzb-1c73-ac1xyzxyz990
vfat       249.7M 152.6M     97.2M  61% /vmfs/volumes/58xyzxyz-cdxyzxyz-766a-12xyzxyz1226
vfat       249.7M 145.3M    104.4M  58% /vmfs/volumes/b4xyzxyz-80xyzxyz-9bf2-e5xyzxyzf6d0

Now that we have the current scratch disk and a list of the sizes of all the disks, we can check if the scratch volume is indeed set to the volume that is 4GB in size.

In the example above we can see that the volume “/vmfs/volumes/5xyzxyz6-dxyzxyzb-1c73-ac1xyzxyz990” is only 285MB in size. That means that this current volume is far too small. No wonder we’re getting an error.

We want to set our scratch disk to a volume that is 4GB in size. According to the list above that means we want to use the volume “/vmfs/volumes/5xyzxyz-1234xyzz-12xy-1234xyzz1234”. To set the desired scratch disk we’ll use the command “ln -sfn <volume_id> /scratch”.

root@ESXi# ln -sfn /vmfs/volumes/5xyzxyz-1234xyzz-12xy-1234xyzz1234 /scratch

If we recheck what the scratch disk is on our host, we’ll see that it is now set to the proper disk volume.

root@ESXi# ls -ll /scratch

lrwxrwxrwx    1 root     root            49 May  8 23:40 /scratch -> /vmfs/volumes/5xyzxyz-1234xyzz-12xy-1234xyzz1234

Now that the scratch disk is properly configured on the host we can update it in VCSA and be done.

From the Host, go to Configure, then Advanced Systems Settings, and click “Edit”.
Select “ScratchConfig.CurrentScratchLocation” and set it to the same value that you just manually configured on host. Hit “Apply”, and you’ll see that the VCSA now recognizes the newly configured scratch disk.

Well now we’re done, and we didn’t even need to reboot a single physical host! You can read more about this error in Nutanix’s KB article about it.

Category: ESXi, Nutanix | LEAVE A COMMENT
5 January 2022

Reset password on locked-out Domain Admin

Sometimes things happen and a password gets forgotten or lost, or in the worst case it wasn’t updated in your password management tool after it was changed. We’ve likely all had to bug another admin to reset our password for one system or another. It happens. But what happens if you are the lone Domain Admin and lock yourself out? Luckily, there is a way to get back in if you do get locked out.

  • Download the Windows Server 2016 ISO.
  • Attach the ISO to your DC virtual machine.
  • Reboot the VM into the ISO
  • Select: Repair your Computer -> Troubleshoot -> Command Prompt
  • At the command prompt, run the following commands:
cd c:\Windows\System32
ren osk.exe osk.old
copy c:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe osk.exe
  • Reboot the Server.
  • Launch the on-screen keyboard and PowerShell will open
  • At the Powershell prompt, run the following command, replacing <PASSWORD> with the password of your choice:
Net user Administrator <PASSWORD>
  • Revert file changes in your System32 folder, renaming ‘osk.old’ back to ‘osk.exe’.

And there you have it folks, you are now able to log back in with your Domain Admin account. This works because while the DC does not have a local Administrator account, it somehow realizes that and resets the Domain Admin. Yes it is a little bit of black magic fuckery in that regard… But it worked and got you back in, so who are we to complain.

Category: Microsoft, Windows 2012/2012R2, Windows 2016, Windows 2019 | LEAVE A COMMENT
30 December 2021

Open and Extract .tar files on Windows

What I’m about to say might be a surprise to you… But you don’t need to install any sort of 3rd party software (like 7zip or WinZip) to extract tarball files on WIndows. Windows 10 actually has the functionality built-in. I know, I was just as surprised to learn about it as you are. From the command line, you can use the “Tar” command to easily extract .tar, .gz, or tar.gz files.

For folks out there that don’t know;

  • A tarball file, ‘.tar’, is just a type of archived file. They are basically, a collection of files that have been merged into one single file.
  • Gzip files, ‘.gz’, are a type of compressed file and it is used to save on the amount of space that a file uses on the hard drive.
  • If you’re following along, then you’ll already have realized that a ‘.tar.gz’ file means that it is just a compressed archive file.

Here’s how to extract your tarball file in Windows 10.

Open the ‘Start Menu’ and search for “cmd”. Right-click on “Command Prompt” and select “Run as administrator“.

Enter the following command inside the window.

tar -xvzf "Path to file" -C "Path to destination"

Example:

tar -xvzf C:\Source\file.tar.gz -C C:\Destination\

This example will extract the contents of the ‘file.tar.gz’ file from the “C:\Source\” folder to the “C:\Destination\” folder. 
Note: Make sure the ‘-C’ parameter before the path to the destination is an uppercase.

The parameters explained:

  • x — instructs tar to extract the archived content.
  • v — verbose mode. This is optional to display the extraction process. Otherwise, you will only see a blinking cursor until the process is complete.
  • z — instructs tar to uncompress the content with gzip.
  • f — provides tar the name of the file you’re about to extract.
  • –C — uppercase and with a hypen, this tells tar to change folders to the specified folder

Category: Microsoft, Windows 10 | 3 Comments on Open and Extract .tar files on Windows
26 November 2021

Nutanix services

Nutanix relies on the following services to run…

  • Acropolis
  • Genesis
  • Zookeeper
  • Zeus
  • Medusa
  • Cassandra
  • Stargate
  • Curator

Acropolis

An Acropolis follower runs on every CVM with an elected Acropolis leader. The Acropolis follower is responsible for statistic collection and publishing and provides VNC proxy capabilities. The Acropolis leader is responsible for stat collection and publishing, task scheduling and execution, VM placement and scheduling, network controller, and VMC proxy.

Genesis

Genesis is a process that runs on each node and is responsible for any services interactions (start/stop/etc.) as well as for the initial configuration. Genesis is a process that runs independently of the cluster and does not require the cluster to be configured/running. The only requirement for Genesis to be running is that Zookeeper is up and running.

Zookeeper

Zookeeper stores information about all cluster components (both hardware and software), including their IP addresses, capacities, and data replication rules, in the cluster configuration. Zookeeper has no dependencies, meaning that it can start without any other cluster components running.

Zookeeper is active on either three or five nodes, depending on the redundancy factor (number of data block copies) applied to the cluster. Zookeeper uses multiple nodes to prevent stale data from being returned to other components. An odd number provides a method for breaking ties if two nodes have different information. Of these nodes, Zookeeper elects one node as the leader. The leader receives all requests for information and confers with its follower nodes. If the leader stops responding, a new leader is elected automatically.

Zeus

Zeus is an interface to access the information stored within Zookeeper and is the Nutanix library that all other components use to access the cluster configuration.

A key element of a distributed system is a method for all nodes to store and update the cluster’s configuration. This configuration includes details about the physical components in the cluster, such as hosts and disks, and logical components, like storage containers.

Medusa

Distributed systems that store data for other systems (for example, a hypervisor that hosts virtual machines) must have a way to keep track of where that data is. In the case of a Nutanix cluster, it is also important to track where the replicas of that data are stored.

Medusa is a Nutanix abstraction layer that sits in front of the database that holds metadata. The database is distributed in a ring topology across multiple nodes in the cluster for resiliency, using a modified form of Apache Cassandra.

Cassandra

Nutanix’s implementation of Cassandra uses a version of Apache Cassandra that has been modified for high performance and automatic, on-demand scaling. Cassandra stores all metadata about the guest VM data in a Nutanix storage container.

Cassandra runs on all nodes of the cluster. Cassandra monitor Level-2 periodically sends a heartbeat to the daemon, which includes information about the load, schema, and health of all the nodes in the ring. Cassandra monitor L2 depends on Zeus/Zk for this information.

Stargate

A distributed system that presents storage to other systems (such as a hypervisor) needs a unified component for receiving and processing data that it receives. The Nutanix cluster has a software component called Stargate that manages this responsibility.

All read and write requests are sent across an internal vSwitch to the Stargate process running on that node. Stargate depends on Medusa to gather metadata and Zeus to gather cluster configuration data. From the perspective of the hypervisor, Stargate is the main point of contact for the Nutanix cluster.

Curator

A Curator leader node periodically scans the metadata database and identifies cleanup and optimization tasks that Stargate should perform. Curator shares analyzed metadata across other Curator nodes. The Curator depends on Zeus to learn which nodes are available, and Medusa to gather metadata. Based on that analysis, it sends commands to Stargate.

Source: Nutanix University’s Enterprise Cloud Administration training

Category: Nutanix | LEAVE A COMMENT