Submitted by prospectsoft on Wed, 08/01/2012 - 06:23
Hi there,
I'd like the created tap interfaces to have the same MTU as the bridge (9000). How best to set this up? I've tried amending the network script on a per-vm basis, but it gets recreated every time I restart a VM.
Obviously by using the default MTU (1500), the bridge MTU is lowered too. The VMs are a mix of Ubuntu and Windows Server (both 2003 and 2008 R2).
Rgds,
Marc
Status:
Closed (fixed)
Comments
Submitted by JamieCameron on Wed, 08/01/2012 - 12:57 Comment #1
Currently there is no way to change this - and in fact, the tap interfaces are created by KVM, not by Cloudmin code.
What problems do the MTU mismatch cause?
Submitted by prospectsoft on Thu, 08/02/2012 - 02:26 Comment #2
The larger MTU gives a faster throughput when transferring large amounts of data (eg databases, server images) between servers. Would be nice to have this available to VMs too. Are the network scripts created by KVM? Because they differ to the default (/etc/qemu-ifup).
I'm referring to the ones created in the "Base directory for virtual systems" , which are usually called hostname-eth0.sh.
Submitted by JamieCameron on Thu, 08/02/2012 - 20:01 Comment #3
Do you also have an MTU set on the interfaces within the VM? I assume that would also be needed to take advantage of the larger bridge and tap device MTUs.
Setting the tap MTU to match the bridge automatically sounds like a good idea though. I'll have Cloudmin do this in the next release.
Submitted by prospectsoft on Fri, 08/03/2012 - 03:36 Comment #4
I would have to do that once the tap interface MTU was set. I'll keep an eye out for the next release.
Cheers,
Marc
Submitted by Issues on Fri, 08/17/2012 - 03:46 Comment #5
Automatically closed -- issue fixed for 2 weeks with no activity.