Ah, that familiar symbol, that welcome to the end of a module.
Congratulations! You have more learning goals that you've put into
your arsenal, and you are really well on your way to progressing in
your career as a Linux system guru.
Come on.
What did we look at?
Well, we've certainly seen a lot about Linux filesystems.
We've seen that we can go through and look at our free space with the
df command, and we can look at the size of a file or maybe even the
size of a directory using the du command.
Using mkfs, we can go through and create filesystems such as xfs,
ext4, and the btrfs filesystems. We can specify the ‑t for type, but
we also have subcommands, mkfs.xfs, etc. Filesystems to be accessible
need to be mounted to a mount point, and that's why we have the mount
and umount command.
Remember, the umount command doesn't have that extra n in it, it's just umount.
If we want to persist any of our filesystems into the mount point,
then we can add them into the /etc/fstab file.
Generally, we want to be using the UUID of the filesystem so we don't get
any clash of hardware where detection, then discovers devices in a
different order on subsequent boots. Using the UUID, we're going to be
assured the filesystem that we determine to be mounted to the mount point
will be. We can gain information about our filesystems with the tune2fs or
dumpe2fs, so this is working with our ext4 filesystem. Now this can be
really useful when we want to go through and start looking at information,
especially about checking our filesystems.
We don't want to turn on our file server and then find that it's going to take
hours to boot because a filesystem has been enforced after the number of
mounts. So we can check the metadata, and if necessary,
change the metadata so it suits our needs.
We have similar tools with xfs, but some of the advantages
of xfs is that we can go through and defrag the
filesystem, so the xfs_fsr command.
Btrfs is a very advanced filesystem, and that has many subcommands.
We'll see more on btrfs when we look at advanced filesystems and how
we can create RAID arrays with a btrfs filesystem.
And that does take us very nicely onto an introduction to the next module, a
module that I really hope you're going to join me in as we take a look at managing advanced filesystems on your Linux systems.