pq2-ls-files-server: 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/pq2-ls-files-server - from package: root-proof-pq2

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

Error in other languages:
pq2-ls-files-server: bevel nie gevind nie
pq2-ls-files-server: comandă negăsită
pq2-ls-files-server: comando não encontrado
pq2-ls-files-server: commande introuvable
pq2-ls-files-server: command not found
pq2-ls-files-server: käsku ei ole
pq2-ls-files-server: không tìm thấy lệnh
pq2-ls-files-server: komanda nerasta
pq2-ls-files-server: Kommando nicht gefunden.
pq2-ls-files-server: kommandot finns inte
pq2-ls-files-server: komut yok
pq2-ls-files-server: nie znaleziono polecenia
pq2-ls-files-server: níor aimsíodh an t-ordú
pq2-ls-files-server: no se encontró la orden
pq2-ls-files-server: no s'ha trobat l'ordre
pq2-ls-files-server: opdracht niet gevonden
pq2-ls-files-server: parancs nem található
pq2-ls-files-server: perintah tidak ditemukan
pq2-ls-files-server: príkaz nenájdený
pq2-ls-files-server: příkaz nenalezen
pq2-ls-files-server: команда не найдена
pq2-ls-files-server: командата не е открита
pq2-ls-files-server: 命令找不到
pq2-ls-files-server: コマンドが見つかりません