Linux/Snippets

File system & drives

List directory sizes

clear;   for each in $(ls) ; do du -hs "$each" ; done

Measure execution time

START=$(date +%s.%N)
command
END=$(date +%s.%N)
DIFF=$(echo "$END - $START" | bc)

show hdd power states

sudo hdparm -C /dev/sd?

Manual SSD Trim

sudo fstrim -v /   

Cron SSD Trim

/etc/scripts/fstrim.sh:

#!/bin/sh
#
echo `date +"%d %b %H:%M:%S"` | tr -d '\n' >> /var/log/fstrim
/sbin/fstrim -v / >> /var/log/fstrim

/etc/cron.d/fstrim:

#
0 * * * * root /etc/scripts/fstrim.sh