Differences in size of data replicated by mirror maker

Hi,

We are using mirrormaker to replicate data between two kafka clusters. I am
seeing huge difference in size of log in data dir between the broker in
source cluster vs broker in destination cluster:

For eg: Size of ~/data/Topic-0/ is about 910 G in source broker, but only
its only 25G in destination broker. I see segmented log files (~500 M) is
created for about every 2 or 3 mins in source brokers, but I see segmented
log files is created for about every 25 mins in destination broker.

I verified mirrormaker is doing fine using consumer offset checker, not
much lag, offsets are incrementing. I also verified that topics/partitions
are not under replicated in both source and target cluster. What is the
reason for this difference in disk usage?