ONTAP Discussions

Ontap 9 Microsoft exchange log storage efficiency


we are having really bad dedup/compression rates on our Exchange 2013 DAG log drive. Volume/LUN separated for each cluster node.

So log volume grows and grows... We are using snapshots back 2 weeks but normally that is not a problem?


500GB data space used:

Total Savings
35.77 GB (2%)
4.06 GB (0%) - Deduplication Savings
31.71 GB (2%) - Compression Savings


Any thoughts? 


DB volume has 10% from total 1,8TB used - I thinks that is normal for Databases.

Total Savings
344.74 GB (10%)
171.84 GB (5%) - Deduplication Savings
172.9 GB (5%) - Compression Savings


any thoughts?






https://www.netapp.com/pdf.html?item=/media/12398-tr-4681pdf.pdf pg 25:

"Deduplication: NetApp recommends deduplication for database volumes, but not for transaction log volumes. Turn on scheduled deduplication and schedule it for nonpeak hours (typically late at night)."


LOG volumes have a high change rate and are not easily deduplicatable. If you have an AFF inline SE will dedupe and compress the data on the fly, which provides some modest space savings at minimal performance hit.


ok so I promoted the volume so I am able to change the scheduler from auto to the default schedule which runs during the night. 

I will keep monitoring now the log volumes and see if it helps or not. 


So this means in an AFF all flash it is set inline per default and the scheduler to auto but it will never do an automatic check for deduplication in the background then? 

all the exchange volumes says idle for 37778:24:09 so since beginning I assume?


So the volume is scanned now but still bad rates. I have a lot of snapshots from the backup (50%) of the data so maybe that is a problem as well?

I have to change the live snapshots to only 2 weeks back, all others will be vaulted but I can't change that right now. 


So I guess I have to live with that?


Last Run Details
Last Run
Nov/05/2020 00:11:11
Total Savings
46.9 GB (4%)
4.31 GB (0%) - Deduplication Savings
42.59 GB (4%) - Compression Savings
Start Time
Nov/05/2020 00:10:06
End Time
Nov/05/2020 00:11:11


Physical Space + Reservations
491.58 GB Data Space Used
553 GB Data Space Available
0 Byte Over Provisioned Space
771.53 GB Used By Snapshot Copies
0 Byte Space available for Snapshot copies
Snapshot Reserve Space: 181.61 GB


Logical Space
1.1 TB Logical Space Used