samtools: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/samtools - from package: samtools

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/samtools - from package: samtools

You may install the required package with command apt-get install {package}

Error in other languages:
samtools: bevel nie gevind nie
samtools: comandă negăsită
samtools: comando não encontrado
samtools: commande introuvable
samtools: command not found
samtools: käsku ei ole
samtools: không tìm thấy lệnh
samtools: komanda nerasta
samtools: Kommando nicht gefunden.
samtools: kommandot finns inte
samtools: komut yok
samtools: nie znaleziono polecenia
samtools: níor aimsíodh an t-ordú
samtools: no se encontró la orden
samtools: no s'ha trobat l'ordre
samtools: opdracht niet gevonden
samtools: parancs nem található
samtools: perintah tidak ditemukan
samtools: príkaz nenájdený
samtools: příkaz nenalezen
samtools: команда не найдена
samtools: командата не е открита
samtools: 命令找不到
samtools: コマンドが見つかりません