LVM or not on Linux VMs

[AnneJanElsinga]

Are there any thoughts on using LVM on Linux VM's?

my personal thoughts are: Why use it. You can expand disks (although not on running VM's) without LVM.

LVM adds an extra level of complexity to your VM's.

I can use mountpoints for adding extra storage so there isn't any need for LVM as well.

So why should I want to use it?

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http://www.vmguru.nl

[AndreTheGiant]

I never use LVN on Linux VM (but also on phyical system).

Mountpoint and symbolic link can be used to reorganize your system without particolar problem.

But some distro use it by default (RHEL for example)...

One benefit (IMHO) of LVM could be the volume snapshot, useful for file server or other cases.

Andre

[AnneJanElsinga]

I totally agree with you, symlinks and mountpoints give you the tools to create a flexibel system without LVM.

Depending on the way you do storage you could also use the snapshotting tools on your storage device, if they support snapshotting multiple volumes at the same time.

Any other thoughts on using LVM or not?

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http://www.vmguru.nl

[AnneJanElsinga]

Too bad there aren't any more thoughts on using LVM or not.

I'm gonna keep it simple then: Not using LVM unless I really really can't do anything else.

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http://www.vmguru.nl

[Texiwill]

Hello,

I actually use LVM on almost all my Linux VMs. The expandability options of joining together multiple VMDKs is much better in my mind than anything else. Specifically if you are joining together VMDKs that will exceed the file size for a given VMFS blocksize. In addition, they do add some other nice features.

In some cases it is far easier and safer to add a new VMDK than it is to 'expand' a VMDK. LVM allows you to do this manipulation without a reboot, granted it all depends on how you build your VMs. I always have a boot disk and then a data disk. In some cases I had to add new disks to the boot to get the necessary 'space' without rebooting a system. LVM helps with that.

Yes mountpoints and symlinks work, but I prefer using LVM. The overhead is not that high and gives me great benefits.

If however you are extremely performance sensitive, then no, you would NOT want to use LVM.

Best regards,
Edward L. Haletky VMware Communities User Moderator, VMware vExpert 2009

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