LVM and storage efficiency

[jollyscots]

Hi All

My experience with virtual servers has been mostly ESXi/Virtual box

With these tools, the admin is able to over commit and under provision.

It is my understanding therefore that normal practice in a virtual environment is to under provision, allow guest OS'es to think they have room to grow, and provide as needed.

I am confused how am I to acheive this when LVM is involved.

I have experimented with ext3 'directory' storage, but this fails to meet my desire for snapshoting, which is a big road block.

With proxmox,how am I to over allocate to my virtual machines?
I understand that LVMs can always be expanded (not sure if i like the concept of a single volume spanning multiple disks/arrays. Id prefer to have my eggs in the one basket, as opposed to two baskets strung together by sticky tape).

But even if I was to expand the LVM group, how would I expand the virtual guest's allocated disk size?

As far as I can see, LVM storage is not providing what I was led to beleive is the crux of virtualisation: The ability to over commit and provide later

Perhaps I am not understanding something?

(I am trying proxmox due what I presumed would be more flexibilty over esxi, but it keeps looking like I may go back to my original idea: A Virtual Box on Ubuntu Desktop setup! For example, the sole-purpose per storage entity restriction is driving me nuts!)

 

[dietmar]

As far as I can see, LVM storage is not providing what I was led to beleive is the crux of virtualisation: The ability to over commit and provide later

Use ext3 on top of an LVM partition (that way snapshots should work) if your really believe over-commit storage is the crux of visualization.

 

[e100]

As far as I can see, LVM storage is not providing what I was led to beleive is the crux of virtualisation: The ability to over commit and provide later

Perhaps I am not understanding something?

(I am trying proxmox due what I presumed would be more flexibilty over esxi, but it keeps looking like I may go back to my original idea: A Virtual Box on Ubuntu Desktop setup! For example, the sole-purpose per storage entity restriction is driving me nuts!)

As dietmar said you can use a file on top of ext3 on top of LVM so you still have snapshot backups.

What happens when all the users decide to use the storage that does not exist?

I choose Proxmox over VMWare because it is more flexible, being open source was just icing on the cake.

 

[jollyscots]

I appreciate your arrogance as you are presumably one of the developers, and as a non-paying customer, I will take it on the chin.

I may try ext3 on top of an LVM, but at this stage I am leaning away from Proxmox as the snapshot backup is currently terribly inefficient anyway.
(http://forum.proxmox.com/threads/2649-KVM-machines-very-slow-unreachable-during-vmtar-backup/page2)

 

[GT1]

I appreciate your arrogance as you are presumably one of the developers, and as a non-paying customer, I will take it on the chin.

holy shit !

i apologise for the incoming rage post, but the amount of stupidity lately on the forums is astounding.

what the fuck do you think this is ? some sort of point and click adventure ? if you want such an "install and forget" scenario, dear sir, please stay with your vmware disneyland and away from this forum.

proxmox is nothing else than a stripped down and customised debian linux with some sophisticated "scripts" to simplify virtualisation. as a bonus you even get a web gui.

most (if not all) of your questions (or however you call them) that you've posted here lately could have been answered if you dared to even touch any random linux distribution, let alone figure out on your own on (as example) why gzip brings one single core up to 100% (hint: simply by googling).

yeah whatever. i like proxmox because i've been using debian since sarge thus it's based on a distro i'm familiar with. if you dont think it'll fit your needs, bugger off and stop posting crap like "i expect a free product to do this but it doesnt so do what i say or i wont use it"

thank you.

 

[e100]

i apologise for the incoming rage post

You are forgiven for saying what many have been thinking.

 

[dietmar]

I appreciate your arrogance as you are presumably one of the developers, and as a non-paying customer, I will take it on the chin.

I just answered your question providing a working solution (within 2 hours response time). So maybe you are the 'arrogant' part here.

 

[jollyscots]

My point was why is gzip using a full core, i.e 4000MIPS, and only producing 10megs a sec.

Whatever man.

Good luck with your business. I won't be contributing any more testing or critique, because you cant f*ing handle it.

Goodbye.

 

[jollyscots]

Dietmar, let me advise you.

You could have answered a constructive answer as to why over commitment is not a significant benifit of virtualisation in your view.

Or perhaps you may have commented that LVM has better means to achieve future expansion.

But all you said was "if your really believe over-commit storage is the crux of visualization."

Which where I come from, is sarcastic and rude.

But again, whatever. The software is removed from my machine, and the CD is destroyed, so no worries, you wont be hearing from me again.

Which is unfortunate, because I consider that I have posted some rather detailed and analytical posts.

 

[dietmar]

Well, somebody is confused - this thread is about 'over commit storage' (you did not even mentioned gzip in this thread)!

 

[jollyscots]

No but Gt1 did.

 

[dietmar]

You could have answered a constructive answer as to why over commitment is not a significant benifit of virtualisation in your view.

Because any jornalling file-system fills up the storage quickly. Besides, I gave you a constructive answer by providing you the solution to your question.

 

[dietmar]

But all you said was "if your really believe over-commit storage is the crux of visualization."

Please can your read the start of that sentence too (that part contains the answer to your question).