cifsiostat: 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 CentOS possible default full paths are:

/usr/bin/cifsiostat - from package: sysstat

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

On Debian possible default full paths are:

/usr/bin/cifsiostat - from package: sysstat

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