This time I want to find out if using any of the following Storage Optimization Options in the job settings makes any difference to the ReFS Block Clone (Veeam Fast Clone) Synthetic Full disk space savings in the long run:
WAN Target 256KB
LAN target 512KB
Local target 1024KB
Local target (large blocks) 4096KB (Worst for deduplication ratio with the "traditional" dedup mechanism)
Thanks!
(I hope these kind of information gets included in the documentation.)
Hi! Smaller blocks will result in space savings regardless of whether you are using backup repository with block cloning is used or not, simply because of the reduced incremental backup size. But you should not be using smaller blocks if you have big VMs and/or direct attached backup storage and/or object storage that charges for API calls, as you will quickly find the impact from smaller blocks does not worth the space savings. Thanks!
Hi Gostev,
Thanks for the reply. Yes I understand smaller blocks result in smaller size backups files and larger blocks are good for large VMs.
But I'm interested in knowing more about the dynamics between these Storage Optimization Options and ReFS Fast Clone Synthetic Full disk saving.
If one job has Local Target 1024KB, another has WAN Target 256KB. Both back up the same VM but to different Repository servers, both doing weekly Synthetic ReFS Fast Clone Full.
If I run Blockstat on both Repositories after 3 months, which job's backup files would be shown to have been referenced MORE times at the block-level (I.e.: better Block Clone disk space saving)?
No additional disk space savings from block cloning here, but ReFS will certainly suffer more due to a few times more cloned blocks and thus more metadata for it to manage.