useful commands when fixing ebs in ec2

To attach: mount /dev/xvdf /vol
To detach: umount /vol
where /vol is the mount point

When you want to re-attach a root device, you have to set the device name to
/sda1 instead of the default name /sdf

If error when trying to mount EBS:

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2
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mount: wrong fs type, bad option, bad superblock on /dev/xvdf,
       missing codepage or helper program, or other error
       In some cases useful info is found in syslog - try
       dmesg | tail  or so

try:
sudo mount /dev/xvdf /vol -t ext4 or sudo mount /dev/xvdf1 /vol -t ext4

Filesystem check: fsck

If any settings wrong, it’s in /etc/fstab