kpsewhich: 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/kpsewhich - from package: texlive

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

On Debian possible default full paths are:

/usr/bin/kpsewhich - from package: texlive-binaries

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

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