Re: [linux-lvm] F7 will not boot after running backup w/snapshot

[malahal@us.ibm.com]

Gerry Reno [greno@verizon.net] wrote:
> Milan Broz wrote:
>> ... After reboot you have no ramdisk, and the Volume Group is incomplete
>> (because you didn't removed PV on ramdisk).
>>   
> And this is no different than if snapshot was on any other device such as 
> esata-hdd, usb-hdd or usb stick.  LVM should handle this.  If the snapshot 
> device goes away, then just vgreduce it on the reboot.
> Trying to retrofit snapshot into existing systems is far easier if you can 
> use ramdisk, esata-hdd, usb-hdd, usb-stick because most systems have 
> allocated all space and rather than struggling through trying to compact 
> and reduce VG, LV, PV, partition, filesystem to gain space it is much 
> easier to use other devices.  And again this is something that LVM should 
> be able to handle.
>> If there is only snapshot, you can recover it, if some operation placed
>> here part of another volume, you will lose data.
>>   
> part of another volume placed where?  on the snapshot?  I don't understand 
> this part.

LVM is not going to distinguish between your /dev/ram1 and other PV's.
So, if you happen to do any 'lvextend/pvmove/lvcreate/anyother'
operations, LVM may place such data on your ram disk. The only operation
that you do after placing /dev/ram1 under LVM is snapshot creation, I
don't see big problem though. You should be very careful to delete the
ram disk PV before you do any operation that involves allocating space.

--Malahal.