Blog et Aide mémoire informatique

mercredi 20 février 2019

Elasticsearch quorum : Split Brain

A quorum is Number of Dedicated Master Nodes / 2 + 1 (rounded down to the nearest whole number), which Amazon ES sets to discovery.zen.minimum_master_nodes when you create your domain. In this case, 2 / 2 + 1 = 2. Because one dedicated master node has failed and only one backup exists, the cluster does not have a quorum and cannot elect a new master. nearest whole number), which Amazon ES sets to discovery.zen.minimum_master_nodes when you create your domain. https://qbox.io/blog/split-brain-problem-elasticsearch

vendredi 1 février 2019

Monitor progress on copy DD command

When you use dd copy,
dd if=/dev/xvdf of=/dev/xvdg bs=4096 
just monitor progress this way.
watch -n5 'sudo kill -USR1 $(pgrep ^dd)'
Some more fancy progress tools : https://www.cyberciti.biz/faq/linux-unix-dd-command-show-progress-while-coping/