[Qemu-devel] Cluster_size parameter issue on qcow2 image format

[PANKAJ RAWAT]

Hi all

I have been working o the qcow2 image format ,

I theory regarding  cluster size it is written that as the size of cluster increase performance should increase.

 

But something surprising happen The performance is degrading as the size of cluster increased from 64K to 1M  ( during expansion of qcow2 image)

 

can any one tell why ?