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Mastering Development System & Network

mysqld crashing almost every hour – mysqld invoked oom-killer

I am running wordpress on a centOS digital ocean droplet my mysql keeps crashing almost every hour — with an out of memory error manually restarting mysqld brings it back up via sudo service mysqld restart Does anyone know what could be causing this? here are my configurations and logs around the time of the […]

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Linux Mastering Development

a gdm-owned /usr/bin/gnome-shell consumes ever more resident RAM in pop!os 20.04: the process should not exist

This is pop!os 20.04 running under X. According to this issue https://gitlab.gnome.org/GNOME/gdm/-/issues/222 once upon a time gnome kept open two gnome shells, one for the user and one for the greeter (running under user gdm). Then it was changed so that after login the greeter’s gnome shell was ‘torn down’. But I have a pop!os […]

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Linux Mastering Development

systemd service stops after startup

My goal is to create a systemd service(foo) that runs a docker container. Before and after the ExecStart , I wanted to invoke a shell script which does some setup/cleanup. I need the cleanup to happen irrespective of the exit code of my ExecStart Since I am running this systemd service in an EC2 instance, […]

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User Help

Starting the docker daemon hangs on Ubuntu 20.04

Docker stopped working for me on Ubuntu 20.04 about two weeks ago. Every docker command hangs and never returns. Neither stopping nor starting the service works. I have to kill -9 /usr/bin/dockerd. I tried to purge and install docker-ce and containerd.io which does not work either. I used the docker repository for this. sudo add-apt-repository […]

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Linux Mastering Development

Does Linux fstrim.service conflict with Windows 10 optimization?

I have the following disk setup, a dual-boot with Windows 10 and Linux Mint 19.3: NAME LABEL SIZE FSTYPE MOUNTPOINT UUID sda 477G ├─sda1 100M vfat /boot/efi AE89-82D6 ├─sda2 16M ├─sda3 WINDOWS-C 476.3G ntfs A4DC8D83DC8D508A └─sda4 505M ntfs BE1AB9201AB8D69D sdb 1.8T ├─sdb1 1G ext2 /boot c360756e-9335-476d-889c-e10026a48c77 ├─sdb2 LINUX-HOME 500G ext4 /home 96ce746c-1934-4774-88df-c9c132604795 ├─sdb3 LINUX-BACKUP 1.2T […]

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Linux Mastering Development

Systemd with multiple instances and restart on fail

I have created with systemd a structure with multiple instances to run the same program several times with different parameters. My intention is that each instance is independent from the others, and in case one fails, it will be restarted, leaving the others unchanged. This is my target unit: [Unit] Description=Cutter After=FD-go-00_tree.service After=FD-go-01_pre.service Requires=FD-go-05_cutter@RC1P111.service FD-go-05_cutter@RC1P112.service […]

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Linux Mastering Development

Investigate through logs why my computer turned off this night

I went to bed at 23h10 yesterday and found my computer (running Debian 10) turned off this morning unexpectedly : it has an inverter with an alarm that would have woken me. I investigated the logs : sudo journalctl sudo more /var/log/syslog sudo more /var/log/messages sudo more /var/log/user.log But found nothing clear about a trouble. […]

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Linux Mastering Development Ubuntu

Newly installed Ubuntu 20.04 freezes

I have an old machine on which I’ve running Ubuntu for years. Last week my HDD died and I revamped my machine buying: SSD Crucial MX500 (500GB) HDD Seagate ST2000DDM008 BARRACUDA (2 TB) I installed a fresh OS on the SSD (to leverage on speed). I partitioned the SSD with 30 GB for the OS, […]

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Mastering Development System & Network

Slurm: “Connection refused” for certain sacctmgr commands

I have an existing slurm cluster up and running but as of today without a configuration change I get an error when I run certain sacctmgr commands and slurmdbd crashes: $ sacctmgr list associations sacctmgr: error: slurm_persist_conn_open_without_init: failed to open persistent connection to slurm.domain.com:6819: Connection refused sacctmgr: error: slurmdbd: Getting response to message type 1410 […]

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Mastering Development System & Network

Slurm: “Connection refused” for certain sacctmgr commands

I have an existing slurm cluster up and running but as of today without a configuration change I get an error when I run certain sacctmgr commands and slurmdbd crashes: $ sacctmgr list associations sacctmgr: error: slurm_persist_conn_open_without_init: failed to open persistent connection to slurm.domain.com:6819: Connection refused sacctmgr: error: slurmdbd: Getting response to message type 1410 […]