06. VMware ESXi Snapshot explained
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- Опубліковано 28 лип 2024
- Today we are going to explore the snapshot action in VMware ESXi.
Main outtakes:
- A snapshot is a restore point for "dependent" virtual hard disks (VMDK) that allows us to revert the disk state to a previous point in time.
- A snapshot creation doesn't require extra space at first, but as the machine works, the delta file grows and consumes datastore space (the file that contains changes after the snapshot is taken).
- The snapshot should not be considered a true "backup", as it's easy to lose data if the parent disk is corrupted or an incorrect user action is taken (1 click).
Music: www.bensound.com - Наука та технологія
Had to watch 3 videos before I got my answer. Thank you. You explained the disk consolidation process which is very important.
Excellent lab and explanation. Thank you!
I hope you are just getting started because you are a great teacher.
Thank you. I am having some rest in mountains as a courtesy of the new year, but I have quite a few videos pre-recorded and planned, so look forward to them :). Thank you for the kind comment.
Thanks for the info, great video and details.
Wow fantastic explanation buddy... love it.
Very good description . Apriciated
Thanks Denis for making this awesome video
Dear Denis, Thanks for sharing such an amazing information. However, I'm not very much clear about how CoW concept is being used here. As per the actual concept, the block which needs to be updated should be written some where else and then actual extent on disk should be updated. Despite the fact, we are saying the changes are being protected on separate delta disk while the original blocks are in freeze state, which sounds like RoW. Could you please shed some light on this. Thanks!
I'm going to have to tinker in a lab to fully get it but this is the best explanation I found on the internet great job. It is actually very misleading that it is called delete as once you understand that in reality there are new files being created, delete seems like you would delete the file (essentially what revert does) so after your video I will try to think of delete as commit or merge. So a few questions...if I understand if you do the parallel thing that the delta's are childs of the parent, but if you do it linearly is one delta the parent of the other or are they all still just childs of the frozen file? does the earlier delta get frozen as well well when you create a new delta? Also if I understand read only from the mother disk but read and write to the delta...what happens when you are in a snapshot and you delete something (file, program, directory etc) that existed before the snapshot...I assume it doesn't actually get rid of it (thus making deleting the snapshot worthless) so I suppose vmware is smart enough just to kind of hide the file or data that you deleted but it never reaches into the parent and actually deletes it? Anyway great video.
How to resolve error vm disk consolidation needed
Hello Abdul. I apologize for late reply, I missed the comment. The error means that during a snapshot removal, the delta disks didn't merge properly with snapshot file. So the first thing you could do is right click the machine and select "consolidate". If it fails, the error message should tell you why. Maybe there's an unresolved lock on the disks of the machine, and a shutdown of the VM or reboot of the host would help. But this message could mean problems with your data, so you will always want to make sure you understand the error that comes up in the vSphere UI.
.nvram ram is not a memory file, it's VM BIOS file
If we take snapshot name sn1 then we restored that snapshot and after restore is done if we delete sn1 snapshot is there going to be any issue since we r using sn1 snapshot in vm