which causes an error "the argument for option '--size' is invalid".
Just round up to the nearest integer to have at least the requested
size. This is similar to what is done for ZFS with d3e3e5d ("When
resizing a ZFS volume, align size to 1M") and makes commands like 'qm
resize 102 scsi1 +0.01G' work.
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>