ceph_smalliobenchdumb: 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/ceph_smalliobenchdumb - from package: ceph-test

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

On Debian possible default full paths are:

/usr/lib/ceph/bin/ceph_smalliobenchdumb - from package: ceph-test

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