kar.2: 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/kar.2 - from package: sra-toolkit

You may install the required package with command apt-get install {package}
Error in other languages:
kar.2: bevel nie gevind nie
kar.2: comandă negăsită
kar.2: comando não encontrado
kar.2: commande introuvable
kar.2: command not found
kar.2: käsku ei ole
kar.2: không tìm thấy lệnh
kar.2: komanda nerasta
kar.2: Kommando nicht gefunden.
kar.2: kommandot finns inte
kar.2: komut yok
kar.2: nie znaleziono polecenia
kar.2: níor aimsíodh an t-ordú
kar.2: no se encontró la orden
kar.2: no s'ha trobat l'ordre
kar.2: opdracht niet gevonden
kar.2: parancs nem található
kar.2: perintah tidak ditemukan
kar.2: príkaz nenájdený
kar.2: příkaz nenalezen
kar.2: команда не найдена
kar.2: командата не е открита
kar.2: 命令找不到
kar.2: コマンドが見つかりません