Out of space – first steps when a datastore runs out of space

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This is a situation that never should happen, and I had to deal with it only a couple of times in more than 10y working with VMware vSphere/ ESXi. In most cases, the reason for this was the usage of thin-provisioned disks together with small datastores. Yes, that’s a bad design. Yes, this should never happen.

There is a nearly 100% chance that this setup will fail one day. Either because someone dumps much data into the VMs, or because of VM snapshots. But such a setip WILL FAIL one day.

Yesterday was one of these days and five VMs have stopped working on a small ESXi in a site of one of my customers. A quick look into the vCenter confirmed my first assumption.… Read more

User vdcs does not have the expected uid 1006

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Sorry for the long delay since my last blog post – busy times, but with lots of vSphere. :) Today, I did an upgrade of a standalone vCenter Server Appliance at one of my healthcare customers. The vCenter was on 6.0 U3 and I had to upgrade it to 6.7 U2. It was only a small deployment with three hosts, so nothing fancy. And as with in many other vSphere upgrades, I came across this warning message:

Warning User vdcs does not have the expected uid 1006
Resolution Please refer to the corresponding KB article.

I saw this message multiple times, but in the past, there was no KB article about this, only a VMTN thread.… Read more

Poor performance with Windows 10/ 2019 1809 on VMFS 6

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TL;DR: This bug is still up to date and has not been fixed yet! Some user in the VMTN thread mentioned a hotpatch from VMware, which seems to be pulled. A fix for this issue will be available with ESXi 6.5 U3 and 6.7 U3. The only workaround is to place VMs on VMFS 5 datastores, or avoid the use of snapshots if you have to use VMFS 6. I can confirm, that Windows 1903 is also affected.

One of my customers told me that they have massive performance problems with a Horizon View deployment at one of their customers. We talked about this issue and they mentioned, that this was related to Windows 10 1809 and VMFS 6. A short investigation showed, that this issue was well known, and even VMware is working on this.… Read more

Make your life easier – KeeAgent for KeePass

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Using a password safe, or password management system, is not a best practice – it’s a common practice. I’m using KeePass for years, because it’s available for different platforms, it can be used offline, it is Open Source, and it is not bound to any cloud services. Keepass allows me securely store usernames, passwords, recovery codes etc. for different services and websites, and together with features like autotype, Keepass offers a plus security and convenience.

I use 2FA or MFA wherever I can. That’s the reason why I’m a big fan of SSH public key authentication. But SSH key handling is sometimes inconvenient.… Read more

Vembu CloudDR – Disaster Recovery as a Cloud Service

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When it comes to disaster recovery (DR), dedicated offsite infrastructure is a must. If you follow the 3-2-1 backup rule, then you should have at least three copies of your data, on two different media, and one copy should be offsite.

But an offsite copy of your data can be expensive… You have to setup storage and networking in a suitable colocation. And even if you have an offsite copy of your data, you must be able to recover the data. This could be fun in case of terabytes of data and an offsite copy on tape.

A offsite copy in a cloud is much more interesting. No need to provide hardware, software, licenses.… Read more

Vembu BDR Essentials – Now up to 10 CPU Sockets

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It is pretty common that vendors offer their products in special editions for SMB customers. VMware offers VMware vSphere Essentials and Essentials Plus, Veeam offers Veeam Backup Essentials, and Vembu has Vembu BDR Essentials.

Now Vembu has extended their Vembu BDR Essentials package significantly to address the needs of mid-sized businesses.

Vembu Technologies/ Vembu BDR Essentials/ Copyright by Vembu Technologies

Affordable backup for SMB customers

Most SMB virtualization deployments consists of two or three hosts, which makes 4 or 6 used CPU sockets. Because of this, Vembu BDR Essentials supportes up to 6 sockets or 50 VMs.… Read more

Securing VMs – vTPM, VBS, KMS and why you should not simply add a vTPM

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Yesterday, I got one of these mails from a customer that make you think “Ehm, no”.

Can you please enable the TPM on all VMs.

The customer

The short answer is “Ehm, no!”. But I’m a kind guy, so I added some explanation to my answer.

Let’s add some context around this topic. The Trusted Platform Module (TPM) is a cryptoprocessor that offers various functions. For example, BitLocker uses the TPM to protect encryption keys. But there are another pretty interesting Windows features that require a TPM: “Virtualization-based Security“, or VBS. In contrast to BitLocker, VBS might be a feature that you want to use inside a VM.… Read more

Notes for a 2-Tier Microsoft Windows PKI

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Implementing a public key infrastructure (PKI) is a recurring task for me. More and more customers tend to implement a PKI in their environment. Mostly not to increase security, rather then to get rid of browser warnings because of self-signed certificates, to secure intra-org email communication with S/MIME, or to sign Microsoft Office macros.

tumbledore / pixabay.com/ Pixybay License

What is a 2-tier PKI?

Why is a multi-tier PKI hierarchy a good idea? Such a hierarchy typically consits of a root Certificate Authority (CA), and an issuing CA. Sometimes you see a 3-tier hierarchy, in which a root CA, a sub CA and an issuing CA are tied together in a chain of trust.… Read more

Veeam B&R: “Rescan of Manually Added” failed

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I got this error in a new deployment of Veeam Backup & Replication 9.5 Update 4. The error occured every day at 9 pm.

The solution to this issue is pretty simple.… Read more

Windows NPS – Authentication failed with error code 16

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Today, a customer called me and reported, on the first sight, a pretty weired error: Only Windows clients were unable to login into a WPA2-Enterprise wireless network. The setup itself was pretty simple: Cisco Meraki WiFi access points, a Windows Network Protection Server (NPS) on a Windows Server 2016 Domain Controller, and a Sophos SG 125 was acting as DHCP for different WiFi networks.

Windows clients failed to authenticate, but Apple iOS, Android, and even Windows 10 Tablets had no problem.

The following error was logged into the Windows Security event log.

… Read more