Editing Troubleshooting

= Health & Performance =

== CPU ==
# cat /proc/cpuinfo
# lscpu
# sensors <- necesita "apt install lm-sensors"
# htop
# mpstat -P ALL 1
# ps aux --sort=-%cpu | head -10 <- cei mai mari 10 consumatori de CPU

== RAM ==
# free -h
# awk '$3=="kB"{$2=$2/1024;$3="MB"} 1' /proc/meminfo | column -t <- conversie in MB
# awk '$3=="kB"{$2=$2/1024**2;$3="GB";} 1' /proc/meminfo | column -t <- conversie in GB
# ps aux --sort=-%mem | head -n 10 <- cei mai mari 10 consumatori de RAM

== Disk ==
# df -h
# df -hi <- arata si inode
# du -hx --max-depth=1 /etc/ | sort -h <- afiseaza toate directoarele si fisierele din /etc/ sortate in ordinea crescatoare a dimensiunii
# du -ah / | sort -rh | head -10 <- arata cele mai mari 10 fisiere sau directoare
# watch -d -n 60 'df -H /dev/sd[a-z][0-9] | sort -r -k 5 -i' <- watch pe "df -h" pentru toate disk-urile montate
# lsblk -f
# fdisk -l

== Status ==
# vmstat 1
# uptime

= Services & Logs =

# systemctl restart <serviciu>
# systemctl start <serviciu>
# systemctl stop <serviciu>

== Journal ==
# journalctl -xb <- logurile de la ultimul boot
# journalctl --since "2026-12-01 10:00" <- loguri incepand cu "2026-12-01 10:00"
# journalctl -u <serviciu> -f <- loguri specifice unui serviciu
# journalctl -xe <- erori recente din journal

== Kernel ==
# dmesg -T
# dmesg --level=err <- filtrare dupa erori

== Network ==
# netstat -tulnp
# ss -tulnp <- afiseaza porturile si socket cu LISTEN activ
# ping -c 3 google.com <- ping catre IP/Domeniu
# traceroute google.co traseul pachetelor catre IP/Domeniu
# lsof -i :443 <- afiseaza porturile si conexiunile (exemplu pt 443)
# tcpdump -i ens18 <- captura de pachete pe din interfata ens18

== Procese ==
# ps aux
# ps aux | grep <serviciu>
# ps axo stat,ppid,pid,comm | grep -w defunct <- identifica procese zombie
# ps -eo pid,ppid,state,cmd | grep " D " <- afiseaza procese aflate in "Uninterruptible Sleep"