[Qemu-discuss] Question about incremental backup on raw disk

[Zhan Adlun]

Hello,
     I use dirty bitmap to backup  raw disks. I export a full raw disk on the 
first backup , then i export a qcow2 disk on the second incremental 
backup.During the backup,the vm is running with several files writing to 
disk(like 'cat /dev/urandom > file').  Then i mege the qcow2 disk to the raw 
disk, it works and all the datas are ok. I donot know it's by chance or not 
because a raw disk doesnot support COW feature. So could any tell me whether 
is's ok to use dirty bitmap to do incremental backup? Thanks.