Updated to Windows 10 killed my Debian GRUB (U)EFI Boot

Submitted by Nikolaus Polak on Sat, 08/01/2015 - 14:18

After the Windows 8 -> Windows 10 Upgrade the Debian testing UEFI Grub2 only showed it's rescue shell. On Debian, I use full disc encryption and have a seperate boot partition - here is how I fixed my Grub without using some LiveCD or Live USB:

On the Grub rescue shell, enter the following - in case you don't know which partition holds what, you can also try > ls (hd0,gpt7)/ [Enter] to get some content information. I knew that number 7 was my dedicated boot partition and number 8 the encrypted root file system.

OSSEC HIDS apt-get update doesn't work (ossec-hids-agent_2.8.2-1wheezy_amd64.deb)

Submitted by Nikolaus Polak on Mon, 07/13/2015 - 16:18

Seems that the OSSEC HIDS packages (for Debian/Ubuntu at least) have somewhere an error in updating the Linux user rights. I had the error only in German and instead of trying to translate it 100% I cut most of the German words simply away:

OpenVZ/Proxmox Container: rsyslog problems after dist-upgrade

Submitted by Nikolaus Polak on Fri, 05/02/2014 - 09:29

Right after a update of Ubuntu Server I faced that rsyslog used 100% CPU and that /var/log/syslog got filled up with following line, which was repeated almost every second:

[rsyslog] imklog: error reading kernel log - shutting down: Bad file descriptor

The problem is, that rsyslog tries to log kernel messages, which is as OpenVZ/Proxmox Container default not possible - to fix this, remove/comment out following line in the file /etc/rsyslog.conf (here already done):

Lighttpd 1.4.35 with PFS on Debian 7 wheezy

Submitted by Nikolaus Polak on Sat, 04/12/2014 - 18:05

After I wrote the howto for Apache2 now a howto for lighttpd and PFS, where I couldn't use "apt-get build-dep lighttpd" because my installed MariaDB packages blocked some mysql-dev-lib packages. Tested on Debian 7 ECC keys and ECDH ciphers working. When you've already do some compiling and apt installing, it should be simple to follow:

1. Preperation - get source and needed tools

Apache 2.2 with PFS on Debian 7 wheezy and Ubuntu 12.04

Submitted by Nikolaus Polak on Sat, 04/12/2014 - 17:16

During I was changing all ssl keys because of the heartbleed bug I thought it is a good time to enable PFS on my Debian 7 und Ubuntu 12.04 LTS servers (ECC keys and ECDH ciphers). Here is a step by step howto, when its not your first time to install something from source it shouldn't be that hard:

1. Preperation - download source and needed tools

Wrong display of free/used diskspace on OpenVZ/Proxmox containers

Submitted by Nikolaus Polak on Sat, 03/22/2014 - 15:56

After I moved some OpenVZ-containers to a new server, the output of "df -h" and "du -sch /" was more different than I ever expected. I guess it was because of some old vzqota-files, because I used earlier existing VEID's.

The solution: Let the quotas get recalculated with following one-liner. Sorryly you've really to switch the OpenVZ-container for a short time offline:

# vzctl stop 199; vzquota drop 199; vzctl start 199

Replace the number "199" with the problematic VEID - now used&free diskspace should be displayed again correctly.

apt-get update: procps ... start: Job failed to start

Submitted by Nikolaus Polak on Wed, 10/16/2013 - 16:49

Seeing an error message during a server upgrade is something you don't want to see - but it seems many people are hit by that Ubuntu bug. Seems my systems were hit because I use OpenVZ (or, better said, Proxmox) for virtualizing my servers.

In the bugreport comments #5 and #11 you'll find the solution: comment out kernel.kptr_restrict = 1 or (re)move the file /etc/sysctl.d/10-kernel-hardening.conf

Now the update process can complete :)

Gentoo as OpenVZ guest - UDEV Problems

Submitted by Nikolaus Polak on Sat, 03/02/2013 - 15:05

During the last weeks I tried to skip the udev update on my Gentoo-OpenVZ- guests (which are running since some years), because the needed kernel versio for OpenVZ-host systems simply doesn't exists. Now I searched for the perfect solution, tried some others - and found the nicest in the in the German Gentoo-Wiki:

Stop udev from starting during system boot:

Ubuntu 12.10 and Amazon suggestions

Submitted by Nikolaus Polak on Fri, 10/05/2012 - 09:52

During the first two beta releases of Ubuntu 12.10 there was a lot of excitement, as the main lens of Unity suddenly showed not only your installed programs and files, there were also Amazon search results. Mark Shuttleworth answered within hours , but some people didn't understand it completely, they thought there will be no easy way to deactivate this new feature.

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