Data Domain Cleaning

If system is filling up, changing default values to more frequent or aggressive cleaning cycles should not be used to compensate this. Running cleaning every day will fragment the data. E.g. read speeds can be severely impaired. Global compression algorithm is dependent on good locality during writes so too frequent clean cycle will in addition bring de-duplication numbers down.

Tim Quan wrote: If system is filling up, changing default values to more frequent or aggressive cleaning cycles should not be used to compensate this. Running cleaning every day will fragment the data. E.g. read speeds can be severely impaired. Global compression algorithm is dependent on good locality during writes so too frequent clean cycle will in addition bring de-duplication numbers down.

I second that.  I see no point of running it on daily basis.  Depending on DDOS, you will see considerable difference in performance impact of cleaning between DDOS 5.1.x, 5.2.x and 5.3.x.

Thanks Guys!

It is not advisable to running cleaning everyday, however, per your needs scheduling it twice a week should be fine, I manage over 68 Data domain around Globe for my clients, depending on the cleanable on each DDR I have their cleaning schedule set. Some once a week is fine, and some high change rates DDRs I run them twice a week with no performance issues.

The Fact, what you see under cleanable on "filesys sh space" is not going to be recovered completely on one cleaning cycle, and considering the size you have under cleanable you can spread your schedule to run two times in a week. I recommend keeping the throttle to 50% though, this will help to run other activities decently. Some other points you can consider while setting up cleaning schedule is if you have a replication pair DDRs, I would have cleaning run on Source first and then on Destination, for eg. Source DDR cleaning schedule is set to run on Monday 6AM, the destination DDR is set to run at tuesday 6AM. This helps to keep both your DDR space synced, when the backups are deleted from the Source, it is reflected to the Destination, so running the clean next day takes care of the recently deleted Data right away.

You can even keep a track of the time it took for each cleaning cycles.

Thanks,

Jignesh Nair