Hello,
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Using hardware not certified for vSAN or for the specific purpose they are certified for is extremely likely to have unpredictable results and from my experience (working with this product 10+ hrs a day for over a year!) these can vary from sub-standard performance all the way to practically non-functional/data-loss.
A key indication that a hardware component will likely have a poor outcome is if it is certified for one use (like the H220 and Hybrid) but not other uses - this basically tells us that it was tested for both and either failed to meet the standards necessary or had real unfixable issues that blocked certification.
The same can be expected with SSDs that are certified for cache-tier in Hybrid but not All-Flash.
Are the cache-tier SSDs SATA? SATA devices have a shallow queue-depth and thus are not ideal for this purpose, I wouldn't advise them for capacity-tier either if this can be avoided.
It may be possible to determine if it is the controller, cache-tier SSDs or capacity-tier SSDs that are the true bottleneck here using vSAN Observer but it is very likely a combination of all of these:
kb.vmware.com/kb/2064240
Enabling Dedupe+Compression initiates a rolling on-disk upgrade which involves evacuating(or deleting if less than 4-nodes) disk-groups on each node and migrating/rebuilding all the data on each node one at a time until all are complete.
Thus the question arises - are you sure the same data has been resyncing for 4 days or has this been adding on data as it resyncs?
You can check this using RVC or the Web Client by looking at the Objects being resynced and noting them.
virten.net/2017/05/vsan-6-6-rvc-guide-part-1-basic-configuration/
Bob
