nepomukmigrator: command not found

Have You tried accessing the binary with the full path?

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/bin/nepomukmigrator - from package: nepomuk-core-runtime

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