We are running a KVM virtualization platform with NFS as storage backend.
The disk images are
qcow2 files (This is "as-is" and we cannot change the setup).
Now we need to move a rather large VM with lots of data to the platform, which was previously hosted on a physical disk based solution (DRBD8)
The dilemma now is: Is it better to create one large (4 TB) qcow2 file or to split it up into smaller qcow2 files (500GB or 1TB) and treat them as individual disks in the VM?
Since the files will be hosted on the same NFS server with the same network connection, I don't think there will be any added bonus regarding bandwidth or IOPS - right ?
It would also be easier to manage the data in the VM under one large disk, as opposed to 4 or 8 small disks.
On the other hand, I think that random reads/writes would probably be faster on multiple files,...
Does someone have any insights or practical experience with this ?