aqsis: 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/aqsis - from package: aqsis-core

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

On Debian possible default full paths are:

/usr/bin/aqsis - from package: aqsis

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

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