We are setting up a new Windows MA with new DD-Engine and a new DiskLib. The DDB disk has been configured with recommended 32k block size and the DiskLib volumes with 64k block size.
We have run a new DASH Copy in the SP to create a new dedup baseline from the previous backed up data. And the plan is to make this DASH Copy the new Primary once all data is available.
A standard re-baseline operation, that usually get better dedup ratio with an updated DD-Engine.
The backup data is mostly Hyper-V vm’s.
In this case the Data Written in the old copy was 9TB and the Copy stopped att 18TB in the new MA as it ran out of resources - DiskLib Full.
This was unexpected.
Now we are thinking about doing Move DDB and MountPath but if there is a general Deduplication degration we are not sure if this will work, and if we will run into the same issues again.
Does anyone have a similar experience or knowledge about this issue and a recommendation on how to move forward?
I have done both new baseline and move DDB many times and always with better dedup ratio in the new MA, I was expecting that here as well.
Best answer by Mike Struening
- Get storage pool details API may not return totalAppSize, totalDataSize and DeDupSavingSize under "DDBDetails" tag Form ID 2790
- Space optimized Auxcopy job may copy jobs out of order if there are partial jobs. Deduplication ratio may be different with similar amount of jobs between primary and dash copy 2473, 2474
I would upgrade accordingly before retrying.