nss_pcache: 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/sbin/nss_pcache - from package: mod_nss

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

On Debian possible default full paths are:

/usr/sbin/nss_pcache - from package: libapache2-mod-nss

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

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