memrm: 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/memrm - from package: libmemcached10
/usr/bin/memrm - from package: libmemcached

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

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