btrace: 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/btrace - from package: blktrace

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

On Debian possible default full paths are:

/usr/sbin/btrace - from package: blktrace

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

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