blkiomon: 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/blkiomon - from package: blktrace

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

On Debian possible default full paths are:

/usr/bin/blkiomon - from package: blktrace

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

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