blkparse: 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/blkparse - from package: blktrace

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

On Debian possible default full paths are:

/usr/bin/blkparse - from package: blktrace

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

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