shrink XFS partition

Below you find a description how to reduce a XFS partition. Important: This contains a full backup and restore of all data because XFS does not support shrinking. Environment Arch Linux (Kernel 5.15.82-1-lts) XFS partition on LVM (vg_root/lv_home) Workflow Boot Arch Linux from an USB drive Mount an USB disk for the backup datamount /dev/sdc1 /mnt/usb Store the UUIDblkid /dev/mapper/vg_root-lv_root > /mnt/usb/uuid Install xfsdumppacman -Sy xfsdump Mount the LVmkdir /mnt/vg_root-lv_homemount […]

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Arch Linux and Veeam Agent: “Failed to collect hostname”

Today I integrated Arch Linux into the Veeam Backup Suite and faced the following error: [04.05.2022 14:38:45.324] <140123638592000> install| >> |Failed to collect hostname [04.05.2022 14:38:45.324] <140123638592000> install| >> |–tr:in std::__cxx11::string CLinuxEpSystemInfoCollector::CollectHostName() const at /mnt/Sources/VeeamInstallerLib/veeaminstallerlib/LinuxEpSystemInfoCollector.cpp:108 Environment Arch Linux (with Kernel 5.16.16, important for veeamsnap) Veeam Agent for Linux Veeam Backup and Replication Solution It took a long time to figure out the problem but the solution is very

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Migrate UniFi Controller from Docker to Dream Machine

Below you find a description how to migrate from a UniFi Controller, running inside Docker, to a UniFi Dream Machine. Environment UniFi Controller 6.5.55 Ubiquiti Dream Machine (UDM) Workflow Install the UDM with default settings Update the UDM and UniFi Controller to the latest version. The UniFi Controller should have the same version as the old controller. Backup the settings from the old Controller Unplug WAN and LAN from your

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Move a UniFi Controller to a new host

Environment UniFi Controller 6.5.55 inside a Docker container Source-Host: Destination-Host: Workflow Stop the Docker container on Source-Host Copy the files to the Destination-Host Start the container on the Source-Host Start the container on the Destination-Host Verify that all devices on the Source-Host are online Verify the devices on the Destination-Host, they should be offline Open the Controller on the Source-Host and change the Controller IP to the Destination-Host.

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Linux Update with LVM Snapshot

Below you find a solution if you want to make a LVM Snapshot before you install the latest Updates. Table of contents 1. Environment2. Create a Snapshot before you install the latest Update3. If the Updates don’t break your system4. If the Updates break you system 1. Environment Partition table sudo fdisk -l /dev/sda Disk /dev/sda: 40 GiB, 42949672960 bytes, 83886080 sectors Disk model: QEMU HARDDISK Units: sectors of 1

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Plant monitoring v0.1

Today I describe a new project to monitor plants: How it looks like when it is integrated into Nagios. GitHub Repository: nagios_check_plant_sensor Table of contents 1. Hardware1.1. Plant sensor1.2. Raspberry Pi 3 Model B​2. Installation​2.1. Raspberry Pi 3 Model B​2.2. Install Python 3.8.*​2.3. Install check_plant_sensor​2.4. Find your sensor’s MAC​2.5. Test check_plant_sensor​2.6. Install NRPE​3. Configure Nagios​3.1. Nagios configuration​4. It’s done​ 1. Hardware 1.1. Plant sensor Manufacturer: WanfeiProduct: Flower Care TesterPrice (21.10.2020):

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oVirt: DataAccessResourceFailureException

From one day to another the oVirt Management Webinterface broke with the Exception: org.springframework.dao.DataAccessResourceFailureException:Error retrieving database metadata; nested exception is org.springframework.jdbc.support.MetaDataAccessException: Error while extracting DatabaseMetaData; nested exception is org.postgresql.util.PSQLException: This connection has been closed. After investigating the log file I found in “/var/log/ovirt-engine-dwh/ovirt-engine-dwhd.log” the following error: org.postgresql.util.PSQLException: ERROR: right sibling’s left-link doesn’t match: block 2 links to 1 instead of expected 4 in index “idx_vm_device_history_vm_id_type” Solution Thanks to Strahil N.,

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oVirt 4.* add HA for HostedEngine

Today I describe how to enable the high available feature in oVirt with two hosts. Normally this should be enabled during adding one host but it can also be enabled afterwards as well. Shut down or migrate all VMs for the given host Put the host into maintenance Reinstall oVirt Set Hosted Engine to “deploy” Now you should see a crown beside the hostname You can migrate the HostedEngine to

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Synchronize multiple Smart Light Bulbs

Today I describe how to synchronize multiple Smart Light Bulbs with one main bulb. You can set the color temperature and brightness for one main lamp, in this example the kitchen, based on this lamp other lamps are synchronized. It is not necessary that the lamps are online during changing the color temperature or brightness. Lights which are offline will get the new configuration after they are turned on. Environment

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GPG high CPU usage

Today I had a very high CPU usage while using GPG. I found the answer inside the following ticket https://dev.gnupg.org/T3972 The high CPU usage was caused by a process like this /usr/bin/gpg –charset utf-8 –display-charset utf-8 –no-auto-check-trustdb –batch –no-tty –status-fd 2 –with-fingerprint –fixed-list-mode –with-colons –list-secret-keys ***** The reason is a huge key in ~/.gnupg/pubring.gpg. Mine was 37MB!!! Thanks to “dkg” who publish the following awk script: < ${GNUPGHOME:-~/.gnupg}/pubring.gpg gpg –list-packets

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