Merci.
La partition de stocage et le disque dur externe sont les deux dernières lignes, la partition systeme sda1 n'apparait pas.
ubuntu@ubuntu:~$ cat /etc/mtab
sysfs /sys sysfs rw,nosuid,nodev,noexec,relatime 0 0
proc /proc proc rw,nosuid,nodev,noexec,relatime 0 0
udev /dev devtmpfs rw,nosuid,relatime,size=1958332k,nr_inodes=489583,mode=755 0 0
devpts /dev/pts devpts rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=000 0 0
tmpfs /run tmpfs rw,nosuid,noexec,relatime,size=394520k,mode=755 0 0
/dev/sr0 /cdrom iso9660 ro,noatime 0 0
/dev/loop0 /rofs squashfs ro,noatime 0 0
/cow / overlay rw,relatime,lowerdir=//filesystem.squashfs,upperdir=/cow/upper,workdir=/cow/work 0 0
securityfs /sys/kernel/security securityfs rw,nosuid,nodev,noexec,relatime 0 0
tmpfs /dev/shm tmpfs rw,nosuid,nodev 0 0
tmpfs /run/lock tmpfs rw,nosuid,nodev,noexec,relatime,size=5120k 0 0
tmpfs /sys/fs/cgroup tmpfs ro,nosuid,nodev,noexec,mode=755 0 0
cgroup /sys/fs/cgroup/systemd cgroup rw,nosuid,nodev,noexec,relatime,xattr,release_agent=/lib/systemd/systemd-cgroups-agent,name=systemd,nsroot=/ 0 0
pstore /sys/fs/pstore pstore rw,nosuid,nodev,noexec,relatime 0 0
efivarfs /sys/firmware/efi/efivars efivarfs rw,nosuid,nodev,noexec,relatime 0 0
cgroup /sys/fs/cgroup/perf_event cgroup rw,nosuid,nodev,noexec,relatime,perf_event,nsroot=/ 0 0
cgroup /sys/fs/cgroup/cpuset cgroup rw,nosuid,nodev,noexec,relatime,cpuset,nsroot=/ 0 0
cgroup /sys/fs/cgroup/cpu,cpuacct cgroup rw,nosuid,nodev,noexec,relatime,cpu,cpuacct,nsroot=/ 0 0
cgroup /sys/fs/cgroup/net_cls,net_prio cgroup rw,nosuid,nodev,noexec,relatime,net_cls,net_prio,nsroot=/ 0 0
cgroup /sys/fs/cgroup/pids cgroup rw,nosuid,nodev,noexec,relatime,pids,nsroot=/ 0 0
cgroup /sys/fs/cgroup/hugetlb cgroup rw,nosuid,nodev,noexec,relatime,hugetlb,nsroot=/ 0 0
cgroup /sys/fs/cgroup/blkio cgroup rw,nosuid,nodev,noexec,relatime,blkio,nsroot=/ 0 0
cgroup /sys/fs/cgroup/memory cgroup rw,nosuid,nodev,noexec,relatime,memory,nsroot=/ 0 0
cgroup /sys/fs/cgroup/devices cgroup rw,nosuid,nodev,noexec,relatime,devices,nsroot=/ 0 0
cgroup /sys/fs/cgroup/freezer cgroup rw,nosuid,nodev,noexec,relatime,freezer,nsroot=/ 0 0
systemd-1 /proc/sys/fs/binfmt_misc autofs rw,relatime,fd=34,pgrp=1,timeout=0,minproto=5,maxproto=5,direct 0 0
hugetlbfs /dev/hugepages hugetlbfs rw,relatime 0 0
mqueue /dev/mqueue mqueue rw,relatime 0 0
debugfs /sys/kernel/debug debugfs rw,relatime 0 0
fusectl /sys/fs/fuse/connections fusectl rw,relatime 0 0
tracefs /sys/kernel/debug/tracing tracefs rw,relatime 0 0
tmpfs /tmp tmpfs rw,nosuid,nodev,relatime 0 0
tmpfs /run/user/999 tmpfs rw,nosuid,nodev,relatime,size=394520k,mode=700,uid=999,gid=999 0 0
gvfsd-fuse /run/user/999/gvfs fuse.gvfsd-fuse rw,nosuid,nodev,relatime,user_id=999,group_id=999 0 0
/dev/sda2 /media/ubuntu/Data fuseblk rw,nosuid,nodev,relatime,user_id=0,group_id=0,default_permissions,allow_other,blksize=4096 0 0
/dev/sdb1 /media/ubuntu/c4ab9b4c-e5d7-463d-8f60-3fab6685d05b ext4 rw,nosuid,nodev,relatime,data=ordered 0 0
ubuntu@ubuntu:~$
ubuntu@ubuntu:~$ ls -la /media/ubuntu/c4ab9b4c-e5d7-463d-8f60-3fab6685d05b
total 248
drwxrwxr-x 20 1000 root 4096 Aug 4 2014 .
drwxrwxr-x+ 4 root root 80 Jan 5 09:41 ..
ubuntu@ubuntu:~$
