gearman: 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/gearman - from package: gearmand

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

On Debian possible default full paths are:

/usr/bin/gearman - from package: gearman-tools

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

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