I launched an EBS backed AMI with all the defaults.
I noticed that it automicatlly had attached an ephemeral disk.
I was just wondering if there was a good programtic way to know that this particular device is ephemeral vs some EBS volume I had decided to attach:
ubuntu@-----:~$ df -ahT
Filesystem Type Size Used Avail Use% Mounted on
/dev/xvda1 ext4 7.9G 867M 6.7G 12% /
proc proc 0 0 0 - /proc
sysfs sysfs 0 0 0 - /sys
none fusectl 0 0 0 - /sys/fs/fuse/connections
none debugfs 0 0 0 - /sys/kernel/debug
none securityfs 0 0 0 - /sys/kernel/security
udev devtmpfs 1.9G 12K 1.9G 1% /dev
devpts devpts 0 0 0 - /dev/pts
tmpfs tmpfs 751M 172K 750M 1% /run
none tmpfs 5.0M 0 5.0M 0% /run/lock
none tmpfs 1.9G 0 1.9G 0% /run/shm
/dev/xvdb ext3 394G 199M 374G 1% /mnt
ubuntu@-----:~$ mount
/dev/xvda1 on / type ext4 (rw)
proc on /proc type proc (rw,noexec,nosuid,nodev)
sysfs on /sys type sysfs (rw,noexec,nosuid,nodev)
none on /sys/fs/fuse/connections type fusectl (rw)
none on /sys/kernel/debug type debugfs (rw)
none on /sys/kernel/security type securityfs (rw)
udev on /dev type devtmpfs (rw,mode=0755)
devpts on /dev/pts type devpts (rw,noexec,nosuid,gid=5,mode=0620)
tmpfs on /run type tmpfs (rw,noexec,nosuid,size=10%,mode=0755)
none on /run/lock type tmpfs (rw,noexec,nosuid,nodev,size=5242880)
none on /run/shm type tmpfs (rw,nosuid,nodev)
/dev/xvdb on /mnt type ext3 (rw,_netdev)