OnCommand Storage Management Software Discussions

Overdeduplication level of the volume

Hi Guys

I saw this error message at Operation manager console


Over deduplication percentage ( 173.68% ) of the volume exceeds the over deduplicated threshold ( 150.00% ). Increase the threshold or resize the volume


can you guys please explain me how can I attend to it as I did not know that you can over deduplicate? where is the setting to Change this threshold??

thanks to all dedupe experts



Re: Overdeduplication level of the volume

The event tries to convey that, if you un-dedupe this volume, the volume cannot contain the data, as its smaller than the volume total size due to dedup which is

The sum of volume used space and saved space (as a result of deduplication) expressed.

So to avoid this, increase the volume size.



Re: Overdeduplication level of the volume

or change the threshold in operations manager

Re: Overdeduplication level of the volume

I have a query. What is Over deduplication. Is it not saved space less than 100%???

Let us say a volume of 100GB, contains 100GB data, upon dedup running it saved 30GB. Hence now, data = 70GB, available (saved) = 30GB. Obvious saved space 30%.

If I un dedup, saved 30GB gonno come back. Still equates to 100%. where comes over dedup

Thanks in advance


Re: Overdeduplication level of the volume

Hi Muthu,

As Adai has explained above, dedup is an event that alerts that you are trying to store the data that may not fit in the volume if you un-dedup per the thresold set volOverDeduplicatedThreshold.

However for the example that you sighted, dedup perecentage is 30% which doesn't look like to be case of over-deduplication. Overdeduplications is when the sum of space savings due to deduplication + data reaches/almost equal to the threshold set i.e. volOverDeduplicatedThreshold percent of the total volume size.



Re: Overdeduplication level of the volume