If you really only care about disk data and nothing more - it's not that expensive to grab more - the question is do you just want summaries of totals across ALL disks or would you prefer data on individual ones? -sd will get you the summary, -sD the details and -sdD both. Anyhow assuming you really want summary as you've indicated above AND if you want it for 5 days, run collectl as a daemon. just edit the line DaemonCommands in /etc/collectl.conf from:
DaemonCommands = -f /var/log/collectl -r00:00,7 -m -F60 -s+YZ
DaemonCommands = -f /var/log/collectl -r00:00,7 -sd -P --sep ','
that will write the csv data to a file in /var/log/collectl, creating a new one each midnight. To start it just do /etc/init.d/collectl start and after 5 days /etc/init.d/collectl stop. The default collection interval is 10 seconds.
The output, which you can generate interactively to look at would be from the command:
"collectl -sd -P --sep ','" and look like the following, noting the interactive default interval is 1 sec:
[root@poker collectl]# collectl -sd -P --sep ','
waiting for 1 second sample...
this should be enough to get you going...