snapshots of vm on LVM over iscsi

[guillermo]

hello all:
Talking about KVM, i have read that only qcow2 support snapshots, but i would like a direct answer to:
Is it posible to do snapshots of a kvm vm on a lvm over iscsi?.
Is it posible to do snapshots of a kvm vm on a lvm over NFS?.
If yes, what filesystem could support this?.
Thaks.

 

[tom]

hello all:
Talking about KVM, i have read that only qcow2 support snapshots,

yes, qcow2 format support snapshots (but these features are not integrated in our gui). And LVM snapshots has nothing to do with filesystems.

but i would like a direct answer to:
Is it posible to do snapshots of a kvm vm on a lvm over iscsi?.

yes.

Is it posible to do snapshots of a kvm vm on a lvm over NFS?.

LVM over NFS is not possible, you need a block device to add LVM on it. NFS is network file system and not a block device.

If yes, what filesystem could support this?.
Thaks.

LVM is directly on block devices, therefore its file system independent.

 

[guillermo]

Thaks for your answer.
Now i am more confuse: When, from the gui, i try to add a harddisk to a kvm vm on a lvm over iscsi, i just can add a raw type and that type does'nt support snapshots.
i mean that i can do "savevm" in the qm shell. I am doing something wrong?.
What a normally do from de gui is :
make a iscsi storage.
make a lvm storage over the iscsi storage created.
create a KVM virtual machine and add a harddisk on the lvm storag created.

thanks

 

[dietmar]

Thaks for your answer.
Now i am more confuse: When, from the gui, i try to add a harddisk to a kvm vm on a lvm over iscsi, i just can add a raw type and that type does'nt support snapshots.

LVM is a block device, and only supports 'raw' format.

 

[guillermo]

LVM is a block device, and only supports 'raw' format.

Thaks dietmar.
So i understand that i can not use "vmsave" with a vm in a LVM storage. But you say that it is posiible to do snapshot of a kvm in a "LVM over iscsi". Would you indicate to me how could i do that?.

Thanks again.

 

[tom]

Thaks dietmar.
So i understand that i can not use "vmsave" with a vm in a LVM storage. But you say that it is posiible to do snapshot of a kvm in a "LVM over iscsi". Would you indicate to me how could i do that?.
Thanks again.

backup with vzdump, using LVM snapshots.

 

[guillermo]

backup with vzdump, using LVM snapshots.

Thanks tom.
I understand that i have to use vzdump to do a copy of my vm in a lvm over iscsi enviroment. Is not a snapshot in the way that kvm vmsave/vmload it is. I mean that when i do the vzdump ( with the option --snapshot , if my vm is running) and i want to restore i really have to "create" a new vmid, or destroy the original and restore in the original store.
So thanks again, and i will begin to read post of vzdump for kvm machines.