svm-train: 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/svm-train - from package: libsvm

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

On Debian possible default full paths are:

/usr/bin/svm-train - from package: libsvm-tools

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

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