Hello, and a warm welcome to this presentation from Pluralsight.
My name is Andrew Mallett,
and I'm going to be your instructor as I guide you through the module
where we take a look at managing advanced file systems.
As we go through and take a look,
we're going to be taking a look at our advanced disk storage
and file systems that we have in Linux.
We can begin by taking a look at logical volume management,
dynamic storage that we can configure within our Linux systems.
We can then move on to software RAID array, where we can then go
through and create our own software RAID environments. Before
moving on to networking, where we can start looking at iSCSI, so
network‑based block storage,
NFS, where we're sharing out UNIX file systems, and CIFS, where we're
sharing out Windows file systems. So when you're ready, sat comfortably,
we shall begin. And we're going to begin,
as I say, by taking a look at logical volume management.
Now with this, we join together all of our physical
volumes at the base of our layer.
So, this is B partitions, this can be disks.
We then group them together into volume groups.
We consume space within a volume group in our logical volumes.
Now, this thing gives you a nice pictorial layout. We can
go through and see a little bit more text if we want a
little bit more explanation,
understanding then that our physical volumes exist at the bottom, and at the
bottom of our layer, we're then looking at raw disk files,
partitions, and disks.
This is our physical storage. Above this, then, we have volume
groups, and volume group acts as storage pools.
These pools aggregate all of our physical storage together to give us
one big volume group or storage repository. From this repository, we can
then go through and start creating our logical volume. Logical volumes
are shown as dev‑mapper devices.
If you saw the previous module, you would have seen dev‑mapper devices
when we were working with our encrypted partition.
But we'll see then that we create our own dev‑mapper devices to
represent the storage that we extract from our volume group.
When we look at managing volume, we have commands to manage our physical
volumes, so commands that start with pv. Commands that start with vg are
for managing our volume groups, and then commands that begin with lv are
our logical volume management.
Now we can go through and take a look at some of
these commands with our pv commands.
We can go through and run a pv scan to look at the available physical volumes.
We can create a physical volume pvcreate, we can display properties of
that physical volume, and we can remove the volume. With our volume group
commands, these commands all start with vg.
So again, we have our vg scan to show us our volume groups, vgcreate to
create a volume group. Here we're enlisting sdb1,
a physical volume. Vgdisplay will show us properties of the volume
group, and vgextend will make more space available to the volume
group by adding in a new physical volume.
If we want to remove the volume group,
it's vgremove. At the top of our stack, we have our logical volumes.
So, lvs would be our logical volume scan to display
the logical volumes. With lvcreate,
we're creating a logical volume. With a lowercase l, we're using then extents,
and we're specifying 100% of the available extents in volume group 1, so all the
available space. We can display properties of our volume group, including
available space with lvdisplay. With lvextend, here we can either use the
lowercase l as before or the uppercase L.
They're interchangeable.
But with the uppercase L, we're specifying to increase by the specified
size, and it will adjust to the nearest physical extent relating to the
500 MB that we've specified. And again, we have lvremove where we want
to remove a logical volume.
Now, while all of this is fun and quite safe to look at when
it's just our slides, it's not really getting that knowledge
embedded into your long‑term memory.
So as always, we encourage you to follow through with a demonstration that's just about to follow. See you there!