Network Connectivity Issues with KVM Backups

[Chris Rivera]

Not sure why or how to fix but recently ive had issues with using any KVM backups.

They work for the most part, but when it gets down to network connectivity theres nothing but issues. The vms can ping solid out side of the box, but if you ping the vm ip address you get more timeouts than you do replies.

This is only for backups. If i create new vms from ghost or iso i have no issues.


Is this something anyone else has ever experienced?

 

[cmassoglia]

I suppose the problem is produced because you restored a backup in a new VM and you didnt change the mac address. Two (or more) same mac address in the same network segment produces sometimes problems like you described

Sorry my bad english.

 

[Chris Rivera]

thanks for the response.

the mac address is already specified by proxmox which does not provide 2 vms with the same mac address.

for ubuntu mac addresses are not stored in the interfaces file
for centos we dont specify specifically a mac address since only 1 nic is present it knows what to use.
for windows mac address is never specified

what im trying to say is we never specify a mac addresses and they work fine... all untill we do a backup and use that backup to restore a new vm.

when we change the ip address it should just work but i can consistently show that ALL KVM (not tested OPENVZ) backups have connectivity issues once they are restored to a new vm.


any ideas? suggestions?

any dumps i can provide to have any help?

 

[dietmar]

the mac address is already specified by proxmox which does not provide 2 vms with the same mac address.

If you restore a VM, the MAC is also restored. Maybe you restored a VM, and keep the old on running too?

 

[Chris Rivera]

Ok this is seeming to make more sence. Let me explain my thought process and see if you can help me figure it out.

I am .. or was using backups as a KVM template... this way if we get 5 people who want windows we dont install 5 times windows from an iso which takes time.

to Restore from a back up takes a few minutes making provisioning minutes not hours.

How would i be able to backup a template of KVM so that i can restore to new vms and provision a new ip

 

[bread-baker]

After restoring the backup, delete the Network Device and add a new one.

Or do the restore from cli.
On pve 1.9 we used to do this, I've not tired on 2.1 :

   qmrestore --unique  /bkup/pvebackup/vzdump-qemu-560-2011_07_24-11_30_05.tar <NEWID>

from the man page for qmrestore : --unique Assign a unique random ethernet address