iolatency: 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/iolatency - from package: perf-tools-unstable

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