IPsec VPN between Sophos UTM and AVM Fritz!Box (LTE) with a dynamic IP-Adresss

Use the following settings to configure a Fritz!Box – also a LTE version – to connect to a Sophos UTM (v9.7)

  • Sophos UTM Settings
  • Fritz!Box VPN VPN-Configfile


Could not find any disk on this device. PRTG error code: PE188

I got this error when I tried to add a SNMP HP ProLiant Physical Disk Sensor for HP Proliant DL 380 G7 with Windows 2012 R2 in our monitoring solution from Paessler (PRTG). The SNMP HP ProLiant System Health, Network and Storage Controller Sensor works fine.

HPE Insight Management Agents and HPE Insight Management WBEM Providers for Windows are installed.

An SNMP walk against OID (used by Paessler for this sensor) works without errors but also without result.

I found some guys with the same probleme and a solution: The problem was the disk (controller) driver. Installed was v8.0.4.0, which seems to be a standard Microsoft driver. With the original HPE controller driver (for us it works.


How to easily migrate a Synology EXT4 volume to Btrfs without data loss

Today I switched from a Synology DS215play to a DS918+. Perfect time to change the file system – the DS215play didn’t support Btrfs. The migration also works with only one device. So I wrote down both ways.

Steps if you haven’t changed your DiskStation:

  1. Backup your data! If you switch to a device with new drives like me, you still have a copy of your data, but if you migrate without new drives, you don’t have a copy! In germany we say: No backup – no pity.
  2. Shut down the DS, remove drive 2. Format drive 2 with your computer.
  3. Turn the DS back on and DO NOT repair the fault volume.
  4. Create a new volume (SHA and Btrfs) in the Storage Manager on drive 2.
  5. For each shared folder, change the location to the new volume. You can only do this for one shared folder at a time and the move may need several hours depending on the size of your shared folders.
  6. When you have moved all the shared folders, shut down your DS and remove drive 1.
  7. Format drive 1 with your computer.
  8. Turn on your DS and go to the Package Center. Repair all apps.
  9. Expand your new volume to drive 1 and wait until RAID Resync is complete. You’re done.

Steps if you are switching to a new DiskStation with new drives (my situation):

  1. Turn off your old DS, remove drive 2.
  2. In the new DS, place the new drives in slot 1 and 2. Place the (old) drive 2 in slot 3.
  3. Turn on the new DS. Open your browser and navigate to the new DiskStation. In my case, the DS got a new IP address. I looked them up in my router DHCP table.
  4. Follow the Migration Wizard and wait until the DS restarts.
  5. Create a new volume (SHA and Btrfs) in the Storage Manager on drive 1 and 2. It is now recommended to change the RAID Resync speed to Fast and wait until RAID synchronization is complete.
  6. Now for each shared folder, change the location to the new volume. You can only do this for one shared folder at a time and may need several hours depending on the size of your shared folders.
  7. When you have moved all shared folders, shut down your DS and remove drive 3.
  8. Turn on your DS and go to the Package Center. Repair all apps. You’re Done.

SSO no longer works with VMware vSphere Client (SEC_ERROR_INADEQUATE_KEY_USAGE)

Last week I noticed that the Single Sign-On (SSO) for the vSphere Client (Flex and HTML5) no longer works in my Firefox. Normally, the VMware Enhanced Authentication Plugin toolbar disappears at the bottom and you can enable the “Using Windows Session Authentication” option, but the checkbox remains unchecked. Reinstalling the VMware Enhanced Authentication plugin, updating the vCenter Server and reinstalling the plugin does not work.

Then I open a ticket at Vmware Support. Hours and some technology later, we had no idea what was going on. But, we find out that the local web server at https://vmware-plugin:8094/ (used by the SSO) displays the following error message in Firefox:


It looks like a problem with the Enhanced Authentication Plugin certificate. This is provided by the plugin. It creates a local web server to communicate with the web page. The VMware support team then created the certificate manually, but the error still occurred – even with IE and Edge.

Then I tried it with a fresh portable Firefox and it worked. In my installed Firefox I removed certificate exceptions for the normal host from the vCenter and vmware-plugin. I also – and most importantly – remove the certificate from the vCenter host and the vmware plugin from the certification authorities in Firefox. Reload the page and it’s working again.

How to Backup and Restore the VMware ESXi 6.x Configuration

Backup Configuration
  • Connect via SSH to your running ESXi Host
  • Run to backup config from host

  • Config saved under /scratch/downloads
  • Copy config to a safe location
Restore Configuration
  • Run enter maintenance mode
  • Run to restore config

Restore Configuration on a blank machine
  • Install Host
    • Install the new host with the same ESXi Version and Build
    • Follow the installation assistent
    • Reboot machine
  • ISO
    • Create a ISO with your backuped configBundle.tgz
    • Burn ISO or Load ISO as Virtual Drive in your LOM
  • ESXi Shell
    • From the Direct Console User Interface, press F2 and Login to access the System Customization menu.
    • Click Troubleshooting Options.
    • Select Enable ESXi Shell and press Return to Enabled.
    • Press Alt+F1 to open the ESXi Shell
  • Mount CD-ROM
    • Load the iso9660 module with

    • Find the Path to the CD-ROM with

    • Set the loaded module to the CD-ROM
    • Now you can see the CD-ROM in the “ls /vmfs/volumes/”
  • Restore config
    • Copy config from mounted CD-ROM Drive to tmp
    • Run to enter maintenance mode
    • Run to restore config

Windows 10 1903 – BSOD (WDF_VIOLATION)

After updating an iMac Late 2010 to Windows 10 1903 I got a blue screen “WDF_VIOLATION”. After checking the minidump, I could see that the MacHALDriver.sys (Macintosh Hardware Application Layer Driver) is involved. After renaming the file (c:\windows\system32\drivers\MacHALDriver.sys) over the network (works because the system crashes after user login) or in safe mode and rebooting, I was able to log back in. Since I don’t use an Apple keyboard I can do without the driver.

While researching I found out that other users also have problems with a similar keyboard driver for HP. In this case it is called HpqKbFiltr.sys. Is also responsible for the hotkeys (screen brightness and co.).

Useful Linux/Unix commands

  • How do I find all files containing specific text?
  • How i change the default file permissions (mask that controls file permissions)


Access to an administrative share failed with “access was denied”

If username and password are right, maybe the UAC are the problem. Try to enable the LocalAccountTokenFilterPolicy to pass the local admin rights.

Run command in background on a Synology NAS with nohup

To run a programm  that doesn’t quit if you close the ssh session use nohup (no hangup). Attention, you have to run it as root for it to work!