zcat: 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:

/bin/zcat - from package: gzip

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

On Debian possible default full paths are:

/bin/zcat - from package: gzip
/bin/zcat - from package: zutils
/usr/lib/klibc/bin/zcat - from package: klibc-utils

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

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