Original subtitles

Snapshots are great tool for a loud environment

Then make changes and experiment with it and return back to the original state

Before we continue I have to emphasize using caution when taking snapshots in a production environment

They're not intended to be used as backups

And running on Snapshot for long periods of time more than a day or two or running off too many snapshots consigna

Magician you shouldn't take snapshots on a virtual machine that syncs with an outside Source such as an active directory server

Neymar has an excellent knowledge base article discussing snapshots

And it has a lot of detail about how snapshots work in the precautions you should take when using them

Let's take a look at using a snapshot

Let me see him one here currently has no snapshots on the virtual machine

If I go to the directory

Where that works machine is being stored

I do a LS Dash L we can see that right now there is a single vmdk file

Take snapshot

We'll call this one

Snapchat one knows I have the option of Snapchatting the virtual machine memory

If I snapshot the memory then I have the option of coming back to a live running virtual machine without the contents of memory the rich

Can I come back to is going to be shut down

For this one I'm not going to take a snapshot of memory I'll click on okay

Watch the processing without memory goes really really quick the reason it goes quick is that we're not making a copy of the heart

Hard drive and then running off of that copy

Instead let's take a look at the drive now

What happens is that the original disk is still there and it has become read only

Emily created a new desk is called a Delta disc

Reeds are going to either come from the Delta disc first if it's a block that's been changed

We're from the original desk if the block that has not been changed since we took the snapshot

Now I have this little Target indicating this is where I'm currently running off of snapshot one which means I'm running off of my

First out the desk

Let's take a second snapshot

And this time I'm going to snapshot the virtual machines memory

Now this one takes significantly longer

As the entire contents of memory of the virtual machine is being written to disk

Once it's completed I now have my second snapshot in nose that has a little green triangle indicating that it has memory and this

Escambia running virtual machine

Notice now I have three vmdk files

My original disk and the first snapshot are both read only now and I'll rights are going to

To the second Delta that's been created

Now any changes I make to the virtual machine are going to be reverted to if I go back to an earlier version of the snaps

That includes changes to the virtual machine Hardware

So if I were to come in here at the settings on this roach machine

A new network adapter

Now we go to monitor

Summary

We'll see that we have two network adapters on this virtual machine

Go back to snapshots

When I select the snapshot and I say

Revert to what I'm saying is I want to delete all of the information that has changed since I took that long

Last snapshot

And it's going to give me a warning

And now I've just jump back in time to the point where I took that snapshot

Go back to summary and we'll see that I only have the single network adapter

If we take a look at the disc

Never going to see that I'm running off of a 03 Delta disc as to got deleted and now I'm running off of a new

When I select delete all

What's going to happen in this case depends on where this little blue Target is

And this example here if I delete all of the snapshots then the data from both of those Delta disc is going to get raw

Rolled back up into the original

Because it's running off of both of those

So we do actions

Delete all snapshots

This has no effect on our running virtual machine we're just consolidating all of the disc back into a single disc we no longer have the

Ability to move back and forth between the snapshots

Now there's no snapshots on this virtual machine

We take a look at Linux VM to situation here is a little bit different

I have four snapshots

First I took a snapshot and that was snapshot one

Then I took a second snapshot on that same chain that became too

Answered one became snapshots free

At that point

I reverted back to the original disc

And took another snapshot and that became for so the chain that I'm running off of where this target is is

1

The data that is on 2 and 3 is not part of my current chain

So when I go to

All actions and delete all snapshots

All of the data that is in two and three is going to be lost forever

One final example here

I'm running off of the second snapshot

Currently and I can select the first one and do a revert to

Now notice now lyrics machine is going to come back powered off

Now I am here

I'm running

In between the first and the second snapshot

If I now delete the second snapshot

All of that information is once again going to go away cuz it's not part of my current running chain

Stop shots are rather complicated so don't get too complex with them however they do make a great tool

For being able to jump back in time

I highly recommend playing around with them and absorbing what happens on the disc when you do so