ceph-coverage: 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/ceph-coverage - from package: ceph

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

On Debian possible default full paths are:

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

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

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