virt-list-partitions: 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/virt-list-partitions - from package: libguestfs-tools

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

On Debian possible default full paths are:

/usr/bin/virt-list-partitions - from package: libguestfs-tools

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

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