Re: [fedora-virt] QCOW2 vs QROW2 Disks [SOLVED]
On 10/29/2012 04:36 AM, Kevin Wolf wrote:
And this is where the copy occurs: qcow2 is organised in clusters,
in
our example with the default 64k cluster size. A cluster can only be
allocated or unallocated as a whole. Now that we're allocating 64k in
sn1.qcow2, but have only 4k to write from our write request, the
remaining 60k must be copied from the backing file so that reading them
gives the same result as before.
Eureka! Thanks Kevin! Now the COW part makes total sense! I searched
the web for this (prior to sending this question) and believe me, I
couldn't find it this relationship (the name and how the cluster
handling works).
Many many thanks!
--
Jorge