Problem snapshot LVM

[naturlight]

Hello everybody.

KVM is working and with ipv6 too.
I tried since 2 days to make a snapshot of a KVM VM.
I did :
qm monitor $veid
savevm $veid

The answer :

Device 'ide0-hd0' is writable but does not support snapshots.

Could you explain me how bypass this ?
My host server is based on LVM for snapshot.

/dev/md1 on / type ext3 (rw,errors=remount-ro)
tmpfs on /lib/init/rw type tmpfs (rw,nosuid,mode=0755)
proc on /proc type proc (rw,noexec,nosuid,nodev)
sysfs on /sys type sysfs (rw,noexec,nosuid,nodev)
procbususb on /proc/bus/usb type usbfs (rw)
udev on /dev type tmpfs (rw,mode=0755)
tmpfs on /dev/shm type tmpfs (rw,nosuid,nodev)
devpts on /dev/pts type devpts (rw,noexec,nosuid,gid=5,mode=620)
/dev/mapper/pve-lv1 on /var/lib/vz type ext3 (rw)

My proxmox version :

running kernel: 2.6.32-4-pve
pve-kernel-2.6.32-4-pve: 2.6.32-28
qemu-server: 1.1-25
pve-firmware: 1.0-9
libpve-storage-perl: 1.0-16
vncterm: 0.9-2
vzctl: 3.0.24-1pve4
vzdump: 1.2-9
vzprocps: 2.0.11-1dso2
vzquota: 3.0.11-1dso1

Thanks for answers
Regards,
QQ

 

[l.mierzwa]

AFAIK savevm command will create qcow2 snapshot, not lvm snapshot, it does not work with lvm or any disk images other than plain file image with qcow2 format.
To do lvm snapshot You must do it on the proxmox host using vzdump.

 

[naturlight]

Hello mierzwa, thanks for info !
vzdump works with KVM ? not only openvz ?

Thanks

 

[l.mierzwa]

Hello mierzwa, thanks for info !
vzdump works with KVM ? not only openvz ?

Thanks

It works with both kvm and openvz.

 

[naturlight]

Great it's works fine thanks !
An other question .. when i make a snapshot .. is it secure ? Is it a full copy of the VM ?
Can i restore the snapshot on an other server ?

Regards,

 

[mmenaz]

I've the feeling that there is a basic misunderstanding here. With vzdump you create a BACKUP and with default parameters is a snapshot backup (on lvm storage ot creates a temporary volume where all subsequent writing are store of "in the while time" writings). So you can then restore that backup on the current proxmox installation or move to a different proxmox server and restore there. You can also specify teh --storage parameter and store in "local" storage or in some LVM added one (or whatever) on the same server.
In any case, to revert back you have to destroy current VM and use qmrestore to restore it (locating the .tar file it created during vzdump backup and specifying as command line parameter, see related manual)