In this video, we'll talk about some tools that allow you to monitor what is going on
in your file system.
We're talking about technical tools that are giving deep insight in the workings of your
file system.
Now, the tools are file system specific.
On EXE4 file systems, Tune2FS will show and optimize your EXE file systems.
There is DumpE2FS, which will dump EXE file system metadata.
And XFS Admin is what you can use to monitor XFS properties.
Let me show you.
For this demo, I'm going to connect to my Ubuntu server for the simple reason that Ubuntu
comes with EXE and CentOS, as well as Red Hat, are coming with XFS by default.
So let me open a root shell, because really for these commands, we do need superuser privileges.
And lsblk is showing me what?
Showing me my root logical volume right here.
And I have an SCA2.
Let's investigate SCA2 using Tune2FS minus L on dev SCA2.
And what do we see?
We see technical information about the file system.
Now, this is not the information that you will be using on a daily basis.
But sometimes, it can be useful to check out file system features, for instance.
There is this feature for the extended attributes.
And these extended attributes are required to store additional information.
Or what do you think of the default mount options, user XATR or ACL?
Let's imagine that you are trying to set an attribute using CHATR, or you are trying to
use setFACL to set file system access control lists, and it doesn't work.
Well, that is a moment where you want to dive into the file system organization to
check if there is ACL support.
And here you can see it.
For the rest of it, you can see more technical metadata.
An interesting one about EXT is that EXT has an inode count.
So there is 114,688 inodes.
Now one feature of EXT is that inodes are static.
They are created when you create your file system.
And that means that you can run out of inodes.
Now fortunately, on this system, we still have a lot of inodes available.
So we are far from this system.
But if ever you get an inode unavailable message, well, requesting information about your file
system might be convenient.
You can get even more data by using the dump utility.
So dump E2FS on dev SCA2, for instance, is giving detailed information about block groups.
This is really going deep, and many administrators never get there.
As you can see in the beginning, we have the same output as tune2fs-l.
But then we get into the block groups.
EXT file systems are organized in block groups for more logical storage of your files.
And if you want details about these block groups, well, you can see it right here.