db2bak: 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 Debian possible default full paths are:

/usr/sbin/db2bak - from package: 389-ds-base

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

Error in other languages:
db2bak: bevel nie gevind nie
db2bak: comandă negăsită
db2bak: comando não encontrado
db2bak: commande introuvable
db2bak: command not found
db2bak: käsku ei ole
db2bak: không tìm thấy lệnh
db2bak: komanda nerasta
db2bak: Kommando nicht gefunden.
db2bak: kommandot finns inte
db2bak: komut yok
db2bak: nie znaleziono polecenia
db2bak: níor aimsíodh an t-ordú
db2bak: no se encontró la orden
db2bak: no s'ha trobat l'ordre
db2bak: opdracht niet gevonden
db2bak: parancs nem található
db2bak: perintah tidak ditemukan
db2bak: príkaz nenájdený
db2bak: příkaz nenalezen
db2bak: команда не найдена
db2bak: командата не е открита
db2bak: 命令找不到
db2bak: コマンドが見つかりません