volume modification

mount empty volume

# see existing filesystem
# if no fs, 'data' will be shown
sudo file -s /dev/xvdf

# make fs
mkfs.ext4 /dev/sdb

mkdir /mnt/a

# mount it onto a directory
mount /dev/sdb /mnt/a

# get block UUID for fstab
blkid

# or use fstab for automated mount
# that will persist restarts
# edit /etc/fstab
# then run mount -a
#<device>   <dir>      <type> <option>                <dump> <fsck>
/dev/sdb    /mnt/a     ext4   defaults,discard        0 0

resize fs

# list block device
lsblk

# disk usage
df -h

# when growing, it is important to grow the partition first before resizing the filesystem
# grow partition
growpart <partition> <partition number>

# extend the file system
resize2fs <volume>

# when shrinking, do the opposite, resize then shrink partition
resize2fs <volume> <size>

# remap partition
parted resizepart <number> <end>

resources

https://wiki.archlinux.org/index.php/Fstab
https://wiki.archlinux.org/index.php/Parted
https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ebs-using-volumes.html