Category Archives: Linux

#DRBD: Promoting the DR site as the main site when PR is failed

By | March 6, 2017

This is a follow up tutorial on the DRBD replication posts about promoting the DR site as the main site when PR is failed. More than a year ago I described in a long tutorial how to use DRBD in a real production environment and the challenges associated to it. See: DRBD based disk replication… Read More »

#DRBD: Gracious role switching of live sites configured with DRBD replication

By | March 6, 2017

This is a follow up tutorial on the DRBD replication posts about gracious role switching of live sites configured with DRBD replication. More than a year ago I described in a long tutorial how to use DRBD in a real production environment and the challenges associated to it. See: DRBD based disk replication of a… Read More »

Linux: Search logs using bash tools

By | February 8, 2017

Sometimes we need to find specific things in application vast logs, sometimes 10 or 20 rotated logs each hundred of MBs each. For a quick search without using some specialized log viewer we can use the very powerful bash text processing commands. Problem: We have 10 log files each 100MB and we need to find… Read More »

Linux: How to remote desktop to Fedora Linux from a Windows 10

By | March 2, 2018

After connecting my two sites using IPSEC see ipsec site-to-site with virtual tunnel interface/ it is easy to ssh to the remote site and OpenVPN see OpenVPN site to site Let us go a step further and activate also remote desktop. I want to be able to connect from my Linux machines but also from… Read More »

Change HP ILO settings without server restart

By | May 26, 2017

I was relocating my servers in a new rack and configuration and decided to put all my ILO ports to a different router with no DHCP. Obviously I ended up with some fake IP6 address defaulted to the ILO device. To make the changes to ILO without a server reboot we have the nice hponcfg… Read More »

EdgeRouter: OpenVPN site-to-site VPN

By | May 28, 2017

I have two sites hosting my home servers so I wanted a solution to have a permanent link between the sites. On site one I have an EdgeRouter POE and on the other site an EdgeRouter Lite and the obvious solution is to have a site to site VPN on a permanent basis. There is… Read More »

Owncloud 8.1.5: File upload error Table ‘homeclouddb.oc_locks’ doesn’t exist”

By | February 9, 2017

After an OwnCloud upgrade I was getting complains from my users that WebDav and OwnCloud windows client were no longer able to upload files. By looking into owncloud.log the following was the repeated error: {“app”:”remote”,”message”:”An exception occurred while executing ‘SELECT * FROM `oc_locks` WHERE `userid` = ? AND (`created` + `timeout`) > 1456517102 AND ((… Read More »

Fedora Linux: Remove graphical mode boot and auto X start

By | February 18, 2016

On my servers I want to completely get read of graphical boot. I do not like fancy graphics that are not compatible with my basic Matrox integrated card and I do not want my system to start directly in X and load the server with unwanted stuff. STEP 1: Remove graphical boot Completely un-install the… Read More »

Fedora Linux: Boot a system from grub prompt

By | February 19, 2016

I had a situation when from a strange reason a default grub setup as a result of a system recovery was missing the lvm and raid modules so I was not able to boot. I have the following setup on the server: – my boot partition is in fact an ext4 partition over a mdraid… Read More »

Fedora Linux: Recover a corrupted system with a RAID1 boot partition with a lvm RAID1 root partition

By | February 19, 2016

There are times when even experimented sysadmins do stupid things. One of that moments happened to me when I tried some speed tests on my ssd RAID1. The result was not so satisfactory. Corrupted /boot partition with missing files and orphan inodes. To make things more complicated I have the following constraints that make this… Read More »