subsample_fasta.py: 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 Debian possible default full paths are:

/usr/lib/qiime/bin/subsample_fasta.py - from package: qiime

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

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