memsup: 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/lib64/erlang/lib/os_mon-2.2.7/priv/bin/memsup - from package: erlang-os_mon

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

On Debian possible default full paths are:

/usr/lib/debug/usr/lib/erlang/lib/os_mon-2.3/priv/bin/memsup - from package: erlang-dbg
/usr/lib/erlang/lib/os_mon-2.3/priv/bin/memsup - from package: erlang-os-mon

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

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