jfs_logdump: 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:

/sbin/jfs_logdump - from package: jfsutils

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

On Debian possible default full paths are:

/sbin/jfs_logdump - from package: jfsutils

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

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