Switched On Tech Design

Author: sotech

  • How to stop apache from starting on boot? Debian 7 and 8

    This little tip is handy for those who want to swap from apache to nginx:

     

    update-rc.d -f apache2 remove

     

    Easy done.

  • OpenSMTPD and Thunderbird: smtp-in: Bad input on session 5.5.1 Invalid command: Pipelining not supported

    While trying to connect to OpenSMTPD running on Debian Stretch Thunderbird couldn’t auto-configure the account and provided the following error in the logs:

     

    email smtpd[566]: smtp-in: Bad input on session 6567905e3020707c: 500 5.5.1 Invalid command: Pipelining not supported

     

    This is a Thunderbird config issue, not a server side issue. Change the settings from SSL/TLS to STARTTLS and that should sort it.

  • Adobe Photoshop Lightroom 5.7 and Mac OS X – will no longer open

    After upgrading Lightroom 5.6 to 5.7, it refused to open with the error:

      Library not loaded: @executable_path/../Frameworks/asneu.framework/versions/a/asneu

     

    This problem stems from the fact that the system drive is a case sensitive file system; in a similar vein, we were recently unable to install Adobe CC on a similar system as it is also incompatible with a case sensitive file system. We fixed our Lightroom issue by changing the path from:

     

    /Applications/Adobe Photoshop Lightroom 5.app/Contents/Frameworks/asneu.framework/Versions/A

     

    to:

     

    /Applications/Adobe Photoshop Lightroom 5.app/Contents/Frameworks/asneu.framework/versions/a

     

    The above assumes a normal install to the /Applications directory. If you are game to try the change yourself, you make the change via Terminal:

     

    cd /Applications/Adobe\ Photoshop\ Lightroom\ 5.app/Contents/Frameworks/asneu.framework

    sudo mv Versions versions

    cd versions

    sudo mv A a

     

    Now try and start Lightroom and you should be successful.

  • HP ProCurve 1810-24G – Where to find the latest firmware updates

    Having trouble locating the latest firmware for your HP ProCurve switch? Here’s where to find it:

     

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  • Proxmox KVM virtual machine: Cannot delete due to missing storage

    Today we encountered a situation where a Proxmox system’s KVM virtual machine refused to delete after the storage volume that it’s virtual HDD resided on was lost; trying to delete the KVM from the web GUI resulted in the following error:

     

    TASK ERROR: storage ‘proxmoxHDD’ does not exists

     

    Attempting to delete it from the command line using:

     

    qm destroy [VM ID]

     

    …resulted in:

     

    storage ‘proxmoxHDD’ does not exists

     

    Fortunately, there’s a way around this. The KVM config files live in:

     

    /etc/pve/qemu-server

     

    Move or erase the [VM ID].conf file and when you refresh your web GUI the VM should be gone.

  • ZFS on Linux: How to find the arc stats (was arcstat.py)

    This has now changed; run the following to find the adaptive read cache stats (ARC):

     

    cat /proc/spl/kstat/zfs/arcstats

     

    You can gleam some really useful information out of how your RAM is being utilised and what your required ARC size might be from the results – this may be a topic for a future post, however!

  • Supermicro X10SRH-CLN4F Socket 2011-3 Server Motherboard Review

    With the recent release of Intel’s Haswell-EP (aka Grantley) range of CPUs we have a new assortment of motherboards to match. One of the Supermicro server offerings is the X10SRH-CLN4F single-socket (UP, as opposed to dual socket – DP) board.

     

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  • ZFS: zpool replace returns error: cannot replace, devices have different sector alignment

    Trying to replace a failed SSD in a zpool we encountered the following error:

     

    cannot replace 4233944908106055 with ata-INTEL_SSDSC2BW240A4_CVD02KY2403GN: devices have different sector alignment

     

    The pool was aligned to 4k sectors – e.g. ashift=12 – whereas the new SSD was aligned to 512b sectors. There’s a quick and easy fix to this – no need to use partitioning tools:

     

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  • Supermicro X10SRH-CLN4F review coming soon!

    We have a new motherboard in-house – the single-socket 2011-3 Supermicro X10SRH-CLN4F. Photos are done, full review to come soon!


    Review is now live! See: https://sotechdesign.com.au/supermicro-x10srh-cln4f-socket-2011-3-server-motherboard-review/

     

    supermicro-x10srh-cln4f-server-motherboard-socket-2011-3-haswell-review-coming-soon

  • How to protect your CentOS server from the Shellshock exploit

    Shellshock is quite a serious security hole found a couple of days ago in Bash; to check whether your CentOS server is vulnerable run the following in a terminal:

    env VAR='() { :;}; echo Shellshock vulnerable!' bash -c "echo Bash Testing"

    If your system is vulnerable, you will see:

    Shellshock vulnerable!

    Bash testing

    If it is not vulnerable, you will see:

    bash: warning: VAR: ignoring function definition attempt
    bash: error importing function definition for `VAR’
    Bash testing

    If you are vulnerable, you can update bash by running the following:

    sudo yum update bash

    Once the update has finished, run the code to check your vulnerability again and it should be sorted.