• Restore the MBR of a Linux installation

    calendar Mar 17, 2016 · 3 min read  ·
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    As preparation for a restore test, I removed the master boot record (MBR) of a Linux system recently:

    1# dd if=/dev/zero of=/dev/sda bs=512 count=1

    This command fills the first 512 bytes (containing the partition table and bootloader) of the first hard drive (/dev/sda) with zeroes (/dev/zero).

    The problem is when you …


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  • Configure LACP under CentOS along with Cisco

    calendar Mar 16, 2016 · 4 min read · cisco  ·
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    <img
  loading="lazy"
  decoding="async"
  alt="LACP setup"
  
    class="image_figure image_internal image_unprocessed"
    src="https://cstan.io/images/2016/03/LAG_Setup.jpg"
  
  
/>

</picture>

    If a host has …


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  • Forgot vCenter Server Appliance root and SSO administrator password

    calendar Feb 18, 2016 · 2 min read · vcsa  ·
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    Loosing the SSO administrator password of vCenter Server Appliance (vCSA) is really bad. Anyhow, this password can be reset, as far as you still have access to the appliance console - this requires the root password. If you also forgot this one, this is really, really, really bad - but also this happens sometimes in …
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  • Short tip: Reset Linux password unattended

    calendar Feb 16, 2016 · 1 min read · kurztipp  ·
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    Sometimes it happens that you lock out yourself from your Linux system. In the worst case, additional security concepts or conditions might hamper access to the system, for example:

    • No root access
    • System cannot be rebooted to reset the password in a chroot session
    • No colleague with system access available

    Recently I …


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  • Analyze and clean-up installed RPM packages with package-cleanup

    calendar Feb 12, 2016 · 2 min read  ·
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    During the installation of kernel updates I stumbled upon a cramped /boot partition recently. Solving this issue is quite easy - e.g. it is possible to manually dig through the RPM database, exclude the running kernel and remove all other packages. Anyhow, this is neither comfortable nor elegant:

    1# yum remove `rpm …

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  • vSphere High Performance Essentials

    calendar Feb 1, 2016 · 3 min read · esxi vcsa  ·
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    New year, new book - some of you might have noticed it: in the last couple of weeks, there were not much updates on my blog. The reason is that I have been working on a second book project. This time I had the pleasure to work as main author on a book about VMware vSphere. Last year, I have already been working as …
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  • IPFire and the AX206 display

    calendar Jan 24, 2016 · 4 min read · ipfire  ·
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    Thanks to the lcd4linux project, Linux also offers the possibility to control LC display - e.g. to display status information. Some years ago, a very cheap digital picture frame was sold on mail-order houses like Pearl. Using an alternative firmware, this device is also capable of being controlled by lcd4linux. Since …
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  • Migrating from IPCop to IPFire

    calendar Jan 19, 2016 · 5 min read · ipcop ipfire  ·
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    Since 2008 I have been using the free Linux distribution IPCop to implement a customized firewall/a router. Of course, DSL providers also equip their customers with routers, but back then I was missing a couple of functions. To name some of them:

    • IPSec / OpenVPN
    • NTP time server
    • DMZ segmentation
    • WLAN access point with …

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  • GitLab Continuous Integration

    calendar Dec 11, 2015 · 7 min read · gitlab  ·
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    With the new major version 8, GitLab was extended to include a continuous integration (CI) component that was developed as dedicated project until now. While it was necessary to utilize external solutions, such as Jenkins, previously, it it now possible to automatically compile and test managed projects easily.

    But, …


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  • Microsoft Active Directory Domain Services authentification under VMware vCenter Server Appliance 6

    calendar Nov 12, 2015 · 2 min read · vcsa  ·
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    For integration in Microsoft environments, VMware offers several Microsoft Active Directory Domain Services (AD DS) connectors in vCenter Server:

    • native integration: vCenter Server is managed as computer object in Active Directory
    • LDAP broker for authentification in Single-Sign-On (SSO)

    When installing the last …


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